Do not ask for message when going invisible
Do not ask user for a message when going invisible, because it's useless. The user can still cancel going invisible with the warning if he is in a groupchat.
Here is a small patch :
diff roster_window_actual_svn.py roster_window.py
1510c1510,1511
\< (show == 'offline' and not gajim.config.get('ask_offline_status')):
---
> (show == 'offline' and not gajim.config.get('ask_offline_status')) or \
> show == 'invisible':