Pull request #4: CAS-13867: Clean up of #ifdef conditional compilations
Merge in CASA/casafeather from CAS-13867 to master
* commit '8504c3e57df0572465c87779b7e392ce6eee21c4':
Do not use USE_GRPC.
Point casa-source to latest commit in CAS-13867
Do not use CASA6 but rather USE_GRPC.
Do not use USE_GRPC.
Contrary to the previous commits, this commit removes USE_GRPC.
This would restore the behaviour as in e94605f1b002382a8842e0dad8238ee65e77cad1
That commit workarounded the casafeather compilation by modifying
the casa-source directly.
Not setting USE_GRPC will have then a equivalent effect