Fix compiler warning unused parameter...

...'count' [-Wunused-parameter]

Author: Rotzbua

DHT.cpp

@@ -37,7 +37,8 @@
  *  @param  count
  *          number of sensors
  */
-DHT::DHT(uint8_t pin, uint8_t type, uint8_t /*count*/) {
+DHT::DHT(uint8_t pin, uint8_t type, uint8_t count) {
+  (void)count; // Workaround to avoid compiler warning.
   _pin = pin;
   _type = type;
 #ifdef __AVR