ipa_restore: Split the services list
    
    Make a proper list from the comma-separated string found in
    the config.
    
    The only current use of backup_services is in run:
        if 'CA' in self.backup_services:
    Without this change, this picked up the 'CA' from 'MEMCACHE'.
    
    Reviewed-By: Tomas Babej <tbabej@redhat.com>