fix #539 (NODEBUG_WEBSOCKETS warning)
fix #539 (NODEBUG_WEBSOCKETS warning)

fix warning when using NODEBUG_WEBSOCKETS as compiler option.
Links2004/arduinoWebSockets,Links2004/arduinoWebSockets,Links2004/arduinoWebSockets,Links2004/arduinoWebSockets,Links2004/arduinoWebSockets,Links2004/arduinoWebSockets