Display gateway url in error

wsapi.go

@@ -204,7 +204,7 @@ func (s *Session) listen(wsConn *websocket.Conn, listening <-chan interface{}) {
 
 			if sameConnection {
 
-				s.log(LogWarning, "error reading from websocket, %s", err)
+				s.log(LogWarning, "error reading from gateway %s websocket, %s", s.gateway, err)
 				// There has been an error reading, close the websocket so that
 				// OnDisconnect event is emitted.
 				err := s.Close()