invite-participant-dialog: stop using tp_channel_group_get_handle_owner()
invite-participant-dialog: stop using tp_channel_group_get_handle_owner()

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

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