host, service: fix adding host/svc with a cert
    
    ipaldap.LDAPEntry expects that entry attributes, if multi-valued,
    are lists.
    
    The recent cert refactoring made it possible to pass certificate
    values from options directly to LDAPEntry. This should now be
    handled in appropriate general way in baseldap.LDAPCreate
    since if options.get() is called, it returns tuple instead
    of list which confuses ipaldap.
    
    https://pagure.io/freeipa/issue/7077
    
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>