Cannot learn code
Very possibly the same issue as #535 but occurs with just one device. I'm using a Broadlink RM Mini 3 D. 

Log looks like:

```
[1/15/2020, 12:50:25 AM] [Broadlink RM] [INFO] Learn Code initializing (undefined)
[1/15/2020, 12:50:25 AM] [Broadlink RM] Learn Code (ready)
[1/15/2020, 12:50:35 AM] [Broadlink RM] [INFO] Learn Code (stopped - 10s timeout)
[1/15/2020, 12:50:35 AM] [Broadlink RM] [INFO] Learn Code (stopped)
```

Tried running homebridge on both raspbian and macOS both with the same result.

Devices gets discovered with no problem:

    [Broadlink RM] [INFO] Discovered Broadlink RM Mini 3 D (5f36) at 192.168.1.8 (a7:df:24:xx:xx:xx)

I've been debugging this issue but I'm stuck in the `message` callback inside the `broadlinkjs-rm` module. There, the bytes at `0x22` and `0x23` are always `251` and `255`, which causes the callback to return. The corresponding code is:

```js
const err = response[0x22] | (response[0x23] << 8);
if (err != 0) {
  return;
}
```

I don't know about the protocol that Broadlink implements, so I don't know what those error codes might mean.

A full log during the 10 seconds before the timeout looks like this. I've included debug statements for the in and outgoing data.

```
[1/15/2020, 2:10:03 AM] [Broadlink RM] [INFO] Learn Code initializing (undefined)
[1/15/2020, 2:10:03 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000ecd000002a276a00020010807a24dfa701000000b2be00001acb92f169b01ab265ab3cf1e6718bf3
[1/15/2020, 2:10:03 AM] [Broadlink RM] Learn Code (ready)
  EventedHTTPServer [::ffff:192.168.1.7] Sending HTTP event '2.10' with data: {"characteristics":[{"aid":2,"iid":10,"value":true}]} +2ms
  EventedHTTPServer [::ffff:192.168.1.4] Muting event '2.10' notification for this connection since it originated here. +1ms
  EventedHTTPServer [::ffff:192.168.1.4] HTTP Response is finished +0ms
[1/15/2020, 2:10:03 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:03 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000d5d1fbff2a27ee03020010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:04 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000030d000002a276a00030010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:04 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:04 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000d6d1fbff2a27ee03030010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:05 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000031d000002a276a00040010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:05 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:05 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000d7d1fbff2a27ee03040010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:06 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000032d000002a276a00050010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:06 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:06 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000d8d1fbff2a27ee03050010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:07 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000033d000002a276a00060010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:07 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:07 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000d9d1fbff2a27ee03060010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:08 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000034d000002a276a00070010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:08 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:08 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000dad1fbff2a27ee03070010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:09 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000035d000002a276a00080010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:09 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:09 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000dbd1fbff2a27ee03080010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:10 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000036d000002a276a00090010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:10 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:10 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000dcd1fbff2a27ee03090010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:11 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000037d000002a276a000a0010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:11 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:11 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000ddd1fbff2a27ee030a0010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:12 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa5500000000000000000000000000000000000000000000000038d000002a276a000b0010807a24dfa701000000b3be00007b173ff2847d25f9f0cb98486335b6d6
[1/15/2020, 2:10:12 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:12 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000ded1fbff2a27ee030b0010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:13 AM] [Broadlink RM] [INFO] Learn Code (stopped - 10s timeout)
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000eed100002a276a000c0010807a24dfa701000000cdbe000096835b2efebd68dccccdf5b14ce150df
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000efd100002a276a000d0010807a24dfa701000000cdbe000096835b2efebd68dccccdf5b14ce150df
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] packet 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000f0d100002a276a000e0010807a24dfa701000000cdbe000096835b2efebd68dccccdf5b14ce150df
[1/15/2020, 2:10:13 AM] [Broadlink RM] [INFO] Learn Code (stopped)
  EventedHTTPServer [::ffff:192.168.1.7] Sending HTTP event '2.10' with data: {"characteristics":[{"aid":2,"iid":10,"value":false}]} +10s
  EventedHTTPServer [::ffff:192.168.1.4] Sending HTTP event '2.10' with data: {"characteristics":[{"aid":2,"iid":10,"value":false}]} +1ms
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] successfuly sent packet - bytes:  72
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000dfd1fbff2a27ee030c0010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
[1/15/2020, 2:10:13 AM] [Broadlink RM] [DEBUG] response 5aa5aa555aa5aa55000000000000000000000000000000000000000000000000e0d1fbff2a27ee030d0010807a24dfa701000000afbe0000f33819a5d873766e00de0fc77d8a8d6a
```


