overview: Clean up unneeded size checks

This was needed when the thumbnails was being requested in this code
path, but since that got moved away there's no point in comparing
with the old value as PhoshActivity will do it by itself.

src/overview.c

@@ -302,17 +302,10 @@ phosh_overview_size_allocate (GtkWidget     *widget,
   children = gtk_container_get_children (GTK_CONTAINER (priv->paginator_running_activities));
 
   for (l = children; l; l = l->next) {
-    gint old_width, old_height;
-    g_object_get (l->data,
-                 "win-width", &old_width,
-                 "win-height", &old_height,
-                 NULL);
-    if (old_width != alloc->width || old_height != alloc->height) {
-      g_object_set (l->data,
-                    "win-width", alloc->width,
-                    "win-height", alloc->height,
-                    NULL);
-    }
+    g_object_set (l->data,
+                  "win-width", alloc->width,
+                  "win-height", alloc->height,
+                  NULL);
   }
 
   g_list_free (children);