lo_message redefined in liblo 0.32

[vishwin]

https://github.com/falkTX/Carla/blob/1e3b910d014f7f7d44e8b3b76eb47efad2121e4f/source/backend/CarlaPlugin.hpp#L27

As of liblo 0.32, specifically radarsat1/liblo@2c1ef1c, this errors in clang:

In file included from CarlaPluginLADSPADSSI.cpp:27:
In file included from ../../utils/CarlaOscUtils.hpp:23:
In file included from /usr/local/include/lo/lo.h:29:
/usr/local/include/lo/lo_types.h:60:29: error: typedef redefinition with different types ('struct lo_message_ *' vs 'void *')
   60 | typedef struct lo_message_ *lo_message;
      |                             ^
../CarlaPlugin.hpp:27:15: note: previous definition is here
   27 | typedef void* lo_message;
      |               ^
1 error generated.

Should probably guard this typedef within #ifndef HAVE_LIBLO.