Incorrect MAC addresses are shown
The MAC address of this device is 78:0f:77:18:35:95, but homebridge-broadlink-rm shows it with the first and third bytes swapped. It would be better not to display a MAC address if it can't be obtained correctly — happy to submit a patch to do this if it would be helpful.

```
[12/31/2018, 10:41:04 AM] [Broadlink RM] [INFO] Discovered Broadlink RM3 Pro Plus (279d) at 192.168.0.12 (77:0f:78:18:35:95)
[12/31/2018, 10:41:16 AM] [Broadlink RM] Broadlink RM device at 192.168.0.12 (77:0f:78:18:35:95) is no longer reachable.
Broadlink RM device at 192.168.0.12 (77:0f:78:18:35:95) has been re-discovered.


```