popup: fix wrong signal emit when remove all button

Summary:
In visuals_set function,
check action_area is NULL, and signal emit action_area,visible/hidden
So, before call visuals_set, action_area should be deleted.

Test Plan: Actually, action area has not min size, so it couldn't be observed.

Reviewers: herb, singh.amitesh, jpeg, cedric, conr2d

Reviewed By: jpeg

Differential Revision: https://phab.enlightenment.org/D5007

src/lib/elementary/elc_popup.c

@@ -637,8 +637,8 @@ _button_remove(Evas_Object *obj,
 
    if (!sd->last_button_number)
      {
-        _visuals_set(obj);
         ELM_SAFE_FREE(sd->action_area, evas_object_del);
+        _visuals_set(obj);
      }
    else
      {