When AUDASPACE couldn't find NUMPY, it would disable WITH_PYTHON for
the rest of Blender. Now setting the value globally is only done for
standalone AUDASPACE builds. Now it's possible to build Blender with
AUDASPACE & PYTHON but without NUMPY.
While this isn't an especially important configuration to support,
having Python mysteriously disabled is a hassle to troubleshoot.
NOTE: extern/audaspace/CMakeLists.txt has become out sync with the
original [0], it seems this is being maintained in our repository.
[0]: https://github.com/neXyon/audaspace/blob/master/CMakeLists.txt