turn off command problem
### Backstory
Hi, can't turn off my windows rig, the shutdown command dont execute, but the ping command work, im running homebridge on windows server, and i tried a lot of comma to turned it off, so i mad a little pytoh web server with ahve 2 routes ping and shutdown homebridge is ok wit hthe ping but the pong not working 

my command to shutdonw is : powershell Invoke-WebRequest http://192.168.1.30:8080/pong 
the same for the ping but with ping instead of pong

ps : the ping command isn't working to display rig status every time but a least it execute the web request (ping command)

### Environment
* win server 2016
* v14.3.0:
* homebridge-wol v4.2.0

### Configuration
My configuration looks like this:
```
    "accessories": [
        {
            "name": "pc",
            "ip": "192.168.1.30",
            "pingInterval": 30,
            "pingsToChange": 1,
            "pingTimeout": 4,
            "pingCommand": "powershell Invoke-WebRequest http://192.168.1.30:8080/ping",
            "mac": "<mac>",
            "wakeGraceTime": 20,
            "shutdownCommand": "powershell Invoke-WebRequest http://192.168.1.30:8080/pong",
            "shutdownGraceTime": 10,
            "log": true,
            "logPinger": true,
            "debugLog": true,
            "returnEarly": false,
            "accessory": "NetworkDevice"
        }
```

### Log

this is the only log i got when i turn off

```
[11/07/2020 à 14:51:15] [pc] Attempting to poll state of "pc" (192.168.1.30) : 0
```

### Notes
thx for any help :) im sure the problem is not about my python program i trid to execute the command on other pc and its working but in hombridge the command dont execute
