_clutter_actor_set_enable_paint_unmapped: don't force an unmap

When enable_paint_unmapped is disabled, we shouldn't force the
source widget to be unmapped if the constraints would keep it
mapped; in practice this shouldn't matter unless a paint handler
is messing with the map state.

https://bugzilla.gnome.org/show_bug.cgi?id=745517

clutter/clutter-actor.c

@@ -15946,7 +15946,7 @@ _clutter_actor_set_enable_paint_unmapped (ClutterActor *self,
     }
   else
     {
-      clutter_actor_update_map_state (self, MAP_STATE_MAKE_UNMAPPED);
+      clutter_actor_update_map_state (self, MAP_STATE_CHECK);
     }
 }