Do not run multiprocessing test if multiprocessing.synchronize is not working

On platforms that do not have a working sem_open implementation, importing
multiprocessing.synchronize will fail with an ImportError. While creating a
multiprocessing.Pool instance, multiprocessing.synchronize will be imported and
might throw an ImportError.

Signed-off-by: Sebastian Ramacher <sebastian+dev@ramacher.at>
1 file changed