Remove contrib/nssciphersuite
    
    The directory contained a script to generate mod_nss configuration
    snippet. Since FreeIPA moved to mod_ssl, it is no longer of use.
    
    Fixes: https://pagure.io/freeipa/issue/5673
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>