Homebridge will not start after installing the latest homebridge-wol update
### Backstory
Hi Alex
I'm using your plugin with Homebridge and also Nodered and everything was working well when I pressed the buttons within the Apple Home App, I could successfully shut down my win10 pc and also wake it up using WoL.

### Issue
However,  I have just installed your update today and now Homebridge will not start unless I first remove my existing config homebridge-wol config.

### Environment
os & os version: FreeNAS-11.2-U7 in a FreeBSD jail.
node version: Node.js v13.3.0
homebridge version: Version 0.4.50
homebridge-wol version: homebridge-wol v4.0.0
Configuration
My configuration looks like this:

{
            "accessory": "NetworkDevice",
            "name": "simon-pc",
            "mac": "<mac-address>",
            "broadcastAddress": "172.16.28.254",
            "wakeGraceTime": 20,
            "shutdownGraceTime": 20,
            "ip": "172.16.28.6",
            "shutdownCommand": "ssh simon@simon-pc shutdown /s /f /t 0"
        },
### Notes

Everything was working until I installed the latest homebridge-wol update.