Fix a logic error when expanding groups in EmpathyIndividualView
Fix a logic error when expanding groups in EmpathyIndividualView

This prevents use of uninitialised memory in the second part of the
expression, and should cause groups to be added to the table of groups to
expand/contract more frequently (correctly). Helps: bgo#628106

GNOME/telepathy-account-widgets,Distrotech/telepathy-account-widgets,GNOME/telepathy-account-widgets,Distrotech/telepathy-account-widgets,GNOME/telepathy-account-widgets