Fix crash when opening GOA facebook account settings
Fix crash when opening GOA facebook account settings

In that case priv->jid_suffix is NULL, so we should not try to call
remove_jid_suffix().

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