push_notifications: Reduce log level for weird warning.

This issue isn't something a system administrator needs to take action
on -- it's a likely minor logic bug around organization
administrators moving topics between streams.

As a result, it shouldn't send error emails to administrators.

zerver/lib/push_notifications.py

@@ -770,7 +770,7 @@ def handle_push_notification(user_profile_id: int, missed_message: Dict[str, Any
             # If the cause is a race with the message being deleted,
             # that's normal and we have no need to log an error.
             return
-        logging.error(
+        logging.info(
             "Unexpected message access failure handling push notifications: %s %s",
             user_profile.id, missed_message['message_id'],
         )

zerver/tests/test_push_notifications.py

@@ -878,13 +878,13 @@ class HandlePushNotificationTest(PushNotificationTest):
 
         # This should log an error
         with mock.patch('zerver.lib.push_notifications.uses_notification_bouncer') as mock_check, \
-                mock.patch('logging.error') as mock_logging_error, \
+                mock.patch('logging.info') as mock_logging_info, \
                 mock.patch('zerver.lib.push_notifications.push_notifications_enabled', return_value = True) as mock_push_notifications:
             handle_push_notification(user_profile.id, missed_message)
             mock_push_notifications.assert_called_once()
             # Check we didn't proceed through.
             mock_check.assert_not_called()
-            mock_logging_error.assert_called_once()
+            mock_logging_info.assert_called_once()
 
     def test_send_notifications_to_bouncer(self) -> None:
         user_profile = self.example_user('hamlet')