pylint: Fix use-maxsplit-arg
    
    Pylint 2.9.0 new checker:
    > Emitted when accessing only the first or last element of str.split().
      The first and last element can be accessed by using str.split(sep,
      maxsplit=1)[0] or str.rsplit(sep, maxsplit=1)[-1] instead.
    
    Fixes: https://pagure.io/freeipa/issue/9117
    Signed-off-by: Stanislav Levin <slev@altlinux.org>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>