account-settings: use empathy_signal_connect_weak to connect the ready signal on managers
account-settings: use empathy_signal_connect_weak to connect the ready signal on managers

If for some reason this signal is fired after the settings has been destroyed,
we shouldn't crash.

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