Reflect changes in boost::asio released in Boost 1.66. (#428)

The service template parameters are disabled by default for now.
Use BOOST_ASIO_ENABLE_OLD_SERVICES macro to enable the old interface.

lib/serializer/Connection.cpp

@@ -14,6 +14,9 @@
 #include "../mapping/CMap.h"
 #include "../CGameState.h"
 
+#if BOOST_VERSION >= 106600
+#define BOOST_ASIO_ENABLE_OLD_SERVICES
+#endif
 #include <boost/asio.hpp>
 
 using namespace boost;