fix: citations always appear in the chatflow app (#3844)

api/core/app/task_pipeline/message_cycle_manage.py

         :param event: event
         :return:
         """
-        self._task_state.metadata['retriever_resources'] = event.retriever_resources
+        if self._application_generate_entity.app_config.additional_features.show_retrieve_source:
+            self._task_state.metadata['retriever_resources'] = event.retriever_resources
 
     def _get_response_metadata(self) -> dict:
         """