contact: compare TpContact objects rather than handles
contact: compare TpContact objects rather than handles

https://bugzilla.gnome.org/show_bug.cgi?id=675229

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