Avoid compilation failure due to protobuf bug on osx

https://code.google.com/p/protobuf/issues/detail?id=119

common/user_level.h

 #ifndef USER_LEVEL_H
 #define USER_LEVEL_H
 
+#ifdef Q_OS_OSX
+// avoid collision from Mac OS X's ConditionalMacros.h
+// https://code.google.com/p/protobuf/issues/detail?id=119
+#undef TYPE_BOOL
+#endif
 #include "pb/serverinfo_user.pb.h"
 #include <QFlags>