check for exact synchronization once per step

hivemind/optim/experimental/progress_tracker.py

@@ -227,7 +227,7 @@ class ProgressTracker(threading.Thread):
         Periodically check the training progress from all peers. Trigger update after target_batch_size total samples
         """
         loop = asyncio.get_event_loop()
-        shutdown_checker = asyncio.create_task(loop.run_in_executor(None, self.shutdown_triggered.wait))
+        shutdown_checker = loop.run_in_executor(None, self.shutdown_triggered.wait)
 
         async def _fetch_progress_unless_shutdown_triggered():
             """Fetch progress, avoid deadlocks if DHT was shut down before this get finished."""