Update topic_reader_asyncio.py

fix linters

Author: alex2211-put

ydb/_topic_reader/topic_reader_asyncio.py

@@ -341,9 +341,7 @@ async def _start(self, stream: IGrpcWrapperAsyncIO, init_message: StreamReadMess
         self._background_tasks.add(asyncio.create_task(self._decode_batches_loop()))
         if self._get_token_function:
             self._background_tasks.add(asyncio.create_task(self._update_token_loop()))
-        self._background_tasks.add(
-            asyncio.create_task(self._handle_background_errors())
-        )
+        self._background_tasks.add(asyncio.create_task(self._handle_background_errors()))
 
     async def wait_error(self):
         raise await self._first_error