Window Cover Bug
Hello Luke,

the window covers seem to work but I get a lot of errors in the log. 

I think that's the bug I've already reported.  I've finished a file for you in the hope that you can start something.

I still can not fully understand the error, it looks like it happens when the window cover closes.

[Report.txt](https://github.com/lprhodes/homebridge-broadlink-rm/files/1811292/Report.txt)

Here is my config:

"name":"Rollo 1 Wohnzimmer",
"type":"window-covering",
"persistState": true,
"resendHexAfterReload": false,
"totalDurationOpen": 29,
"totalDurationClose": 27,
"disableLogs": false, 
"host":"192.168.6.48",
"data":{
"open":"",
"close":"",
"stop":""
}
},
