Fix storing login plugin status and order

Fix storing login plugin status and order

When plugins were enabled or disabled their status was not stored
in the database, unless the order was explicitly manipulated.
Moreover if the order was changed that fact would not be refrlected
in the actual authntication order until a restart.
Fix the code to always permanently store the enabled/disabled status,
and to immediately change the authentication order.

Signed-off-by: Simo Sorce <simo@redhat.com>
Reviewed-by: Patrick Uiterwijk <puiterwijk@redhat.com>