Set pin for RAK-12039 to allow I2C auto-detect (#2555)

* SET pin for RAK-12039 and put back macaddr for now

* Guard against epaper RAK variant

* Update main.cpp

* Add these back

src/main.cpp

@@ -263,6 +263,12 @@ void setup()
     // We need to enable 3.3V periphery in order to scan it
     pinMode(PIN_3V3_EN, OUTPUT);
     digitalWrite(PIN_3V3_EN, HIGH);
+
+#ifndef USE_EINK
+    // RAK-12039 set pin for Air quality sensor
+    pinMode(AQ_SET_PIN, OUTPUT);
+    digitalWrite(AQ_SET_PIN, HIGH);
+#endif
 #endif
 
     // Currently only the tbeam has a PMU