message: Tune websocket echo server for performance
diff: @@ -160,6 +160,8 @@ private:
  auto& d = *d_;
  d.ws.set_option(decorate(identity{}));
  d.ws.set_option(read_message_max(64 * 1024 * 1024));
  + d.ws.set_option(auto_fragment{false});
  + d.ws.set_option(write_buffer_size{64 * 1024});
  run();
  }
  