Resolve issue causing demo project to crash on esp8266 (#142)

Exception 3, Exception 9 and Exception 28 are thrown sporadically if printing to serial during WebSocket RX
Believed to be due to serial buffer causing RX to block, investigating as part of #123

src/LightStateService.cpp

@@ -40,7 +40,6 @@ void LightStateService::begin() {
 }
 
 void LightStateService::onConfigUpdated() {
-  Serial.printf_P(PSTR("The light is now: %s\r\n"), _state.ledOn ? "on" : "off");
   digitalWrite(BLINK_LED, _state.ledOn ? LED_ON : LED_OFF);
 }