Added a pragma message if MQTT is disabled.

src/mqtt.cpp

@@ -1,7 +1,9 @@
 #include "my_mqtt.h"
 #include "config.h"
 
-#ifdef MQTT_ENABLE
+#ifndef MQTT_ENABLE
+	#pragma message "MQTT_ENABLE is false. Skipping MQTT."
+#else
 
 #include <ESP8266WiFi.h>
 #include <PubSubClient.h>