Make the compilation of M17 conditional.

M17Network.cpp

@@ -1,5 +1,5 @@
 /*
- *   Copyright (C) 2020,2021 by Jonathan Naylor G4KLX
+ *   Copyright (C) 2020,2021,2023 by Jonathan Naylor G4KLX
  *
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU General Public License as published by
@@ -19,10 +19,11 @@
 #include "M17Network.h"
 #include "M17Defines.h"
 #include "M17Utils.h"
-#include "Defines.h"
 #include "Utils.h"
 #include "Log.h"
 
+#if defined(USE_M17)
+
 #include <cstdio>
 #include <cassert>
 #include <cstring>
@@ -213,3 +214,6 @@ void CM17Network::sendPing()
 
 	m_socket.write(buffer, 4U, m_addr, m_addrLen);
 }
+
+#endif
+