the permanent error after a random disconnection

[marek-veber]

Hi, I'm using this nice library in home-assistant, but I found (and solved) an issue after a disconnection there.

See: blindlight86/HA_USR-R16#5

The problem can be solved by updating handle_disconnect_callback function:

$ diff protocol-old.py protocol.py 
293a294,296
>         self.active_transaction = None
>         self.in_transaction = False
>         self.active_packet = None

I will create a pull request with the fix.