fix: concurrent write to websocket connection

internal/msggateway/client.go

@@ -446,11 +446,11 @@ func (c *Client) handlerTextMessage(b []byte) error {
 		if err != nil {
 			return err
 		}
+		c.w.Lock()
+		defer c.w.Unlock()
 		if err := c.conn.SetWriteDeadline(writeWait); err != nil {
 			return err
 		}
-		c.w.Lock()
-		defer c.w.Unlock()
 		return c.conn.WriteMessage(MessageText, msgData)
 	default:
 		return fmt.Errorf("not support message type %s", msg.Type)