change pin assignement name

#177 in some case the compiler doesn't interpret D1 to 5, so as to avoid
that we put directy 5 instead of D1 for ESP8266

config_DHT.h

@@ -36,7 +36,7 @@
 #define DHT_SENSOR_TYPE DHT22 //uncomment for DHT22 Sensor (default for backwards compatibility)
 /*-------------------PIN DEFINITIONS----------------------*/
 #if defined(ESP8266)
-  #define DHT_RECEIVER_PIN D1 // you can put D5 if you don't use HCSR501 sensor and the RFM69
+  #define DHT_RECEIVER_PIN 5 //5 = D1 you can put 14 = D5 if you don't use HCSR501 sensor and the RFM69
 #elif defined(ESP32)
   #define DHT_RECEIVER_PIN 35
 #else