Always clear the mirror image data pointer

Under wayland evas will sometimes use the old one, I have no idea why.
Fixes a crash bug when mousing out of menus in a GTK app under wayland.

fix T3576

src/bin/e_comp_object.c

@@ -3798,9 +3798,8 @@ e_comp_object_dirty(Evas_Object *obj)
      {
         //evas_object_image_border_set(o, bx, by, bxx, byy);
         //evas_object_image_border_center_fill_set(o, EVAS_BORDER_FILL_SOLID);
+        evas_object_image_data_set(o, NULL);
         evas_object_image_pixels_dirty_set(o, dirty);
-        if (!dirty)
-          evas_object_image_data_set(o, NULL);
         evas_object_image_size_set(o, w, h);
         visible |= evas_object_visible_get(o);
      }