Fix scene dock search losing its default tooltip after typing an invalid filter

editor/scene_tree_dock.cpp

@@ -3330,7 +3330,7 @@ void SceneTreeDock::_filter_changed(const String &p_filter) {
 		filter->set_tooltip_text(warning);
 	} else {
 		filter->remove_theme_icon_override(SNAME("clear"));
-		filter->set_tooltip_text("");
+		filter->set_tooltip_text(TTR("Filter nodes by entering a part of their name, type (if prefixed with \"type:\" or \"t:\")\nor group (if prefixed with \"group:\" or \"g:\"). Filtering is case-insensitive."));
 	}
 }