Ansible launcher: log reconfiguration complete

So we're not on the edge of our seats.

Change-Id: I4117142e63d8edd6ac6f163883bb4c8e2b7e06da

zuul/launcher/ansiblelaunchserver.py

@@ -158,6 +158,7 @@ class LaunchServer(object):
             except Exception:
                 self.log.exception("Exception sending reconfigure command "
                                    "to worker:")
+        self.log.debug("Reconfiguration complete")
 
     def stop(self):
         self.log.debug("Stopping")