mod_muc_bot: Save occupant to room
This has some side-effects:
Firstly, the bot shows up in occupant list, which is nice. Secondly, the
bot starts receiving messages from the room which might be wanted, but
it would be better to join the room for real in this case.
16 Your connection is encrypted using the %s protocol, which has been demonstrated to be insecure and will be disabled soon. Please upgrade your client.