ensure we set channel in lock

_set_current_channel must be called  with a lock

Change-Id: I151564670946b3399158352c51d1670b9e7291fb

oslo_messaging/_drivers/impl_rabbit.py

@@ -607,6 +607,7 @@ class Connection(object):
         self._heartbeat_support_log_emitted = False
 
         # NOTE(sileht): just ensure the connection is setuped at startup
+        with self._connection_lock:
             self.ensure_connection()
 
         # NOTE(sileht): if purpose is PURPOSE_LISTEN