Status updates stops comming to mqtt after some time
**System**
SP7000
TM70
serial connection to RPI3 where openhab2 and its embeded MQTT server is running
python 3.6
pai running as a service.

**Describe the bug**
For some reason pai stops posting updates to mqtt after some time -hard to say, maybe 20min to few hours. At least after a night its always stopped. Command topic is still read by pai- i can arm,etc. There in nothing in the log (INFO level). 
Also i`m not sure if its supposed to work for my setup, but based on code i guess it should - i do not get ac,dc,vdc updates at any time, event then everything else if working.

**To Reproduce**
Just run pai for longer time period and status updates to MQTT stops. 

**Logs**
I will try to collect them in DEBUG, since at INFO level there is nothing to catch on.
