cert: do not limit internal searches in cert-find
    
    Instead, apply the limits on the combined result.
    
    This fixes (absence of) `--sizelimit` leading to strange behavior, such as
    `cert-find --users user` returning a non-empty result only with
    `--sizelimit 0`.
    
    https://pagure.io/freeipa/issue/6716
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>