Also works without wifi

ampel-firmware/ampel-firmware.ino

@@ -68,6 +68,7 @@ void setup() {
 
   web_config::initialize();
 
+#ifdef AMPEL_WIFI
   web_config::setWifiConnectionCallback([]() {
     //TODO: Move somewhere else
     led_effects::showKITTWheel(color::green);
@@ -93,6 +94,7 @@ void setup() {
     led_effects::showKITTWheel(color::red);
     Serial.println(F("Connection to WiFi failed"));
   });
+#endif
 
   void setWifiConnectionFailedCallback(void (*function)());