Fix press save in Import Defaults did not save the changed setting

editor/import_defaults_editor.cpp

@@ -109,6 +109,7 @@ void ImportDefaultsEditor::_save() {
 		} else {
 			ProjectSettings::get_singleton()->set("importer_defaults/" + settings->importer->get_importer_name(), Variant());
 		}
+		ProjectSettings::get_singleton()->save();
 	}
 }