position_menu_under_button() receives extra arguments
Bug description
position_menu_under_button() takes 2 positional arguments but 4 were given
Steps to reproduce
Click on 'chow advanced functions' or any other button creating a menu on chat control panel.
Software versions
0.16.10 A GTK+ Jabber/XMPP client GTK+ Version: 3.18.6 PyGobject Version: 3.18.2 python-nbxmpp Version: 0.5.3