roster-window: display messages when roster is empty
roster-window: display messages when roster is empty

https://bugzilla.gnome.org/show_bug.cgi?id=677948

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