Update button constructor

Transmitter/src/Button.cpp

@@ -10,7 +10,7 @@ class Button {
 	void (*_releaseCallback)(void);
 
 public:
-	Button(int pin, void (*pressCallback)(void), void (*releaseCallback)(void)) {
+	Button(unsigned int pin, void (*pressCallback)(void), void (*releaseCallback)(void)) {
 		_pin = pin;
 		_pressCallback = pressCallback;
 		_releaseCallback = releaseCallback;