Since the output needs to be the same, regardless if the module is
compressed, change populate-modules.sh to conditionally compress the
module if that feature is enabled.
This way we can execute the tests with any build-time configuration and
it should still pass.
Suggested-by: Michal Suchánek <msuchanek@suse.de> Reviewed-by: Michal Suchánek <msuchanek@suse.de> Tested-by: Michal Suchánek <msuchanek@suse.de> Reviewed-by: Petr Vorel <pvorel@suse.cz>