fixed lint

Author: daniel-sanche

google/cloud/bigtable/data/_async/client.py

@@ -480,7 +480,9 @@ async def _manage_channel(
             old_channel = super_channel.swap_channel(new_channel)
             self._invalidate_channel_stubs()
             # give old_channel a chance to complete existing rpcs
-            await CrossSync.event_wait(self._is_closed, grace_period, async_break_early=False)
+            await CrossSync.event_wait(
+                self._is_closed, grace_period, async_break_early=False
+            )
             await old_channel.close()
             # subtract the time spent waiting for the channel to be replaced
             next_refresh = random.uniform(refresh_interval_min, refresh_interval_max)