Require Dogtag PKI 10.6.8-3
    
    pki-core 10.6.7 was unpushed and never landed in Fedora stable. The
    latest release is 10.6.8-3 with additional fixes. The new versions are
    in testing and FreeIPA's master COPR.
    
    Also remove dependency on JSS. The dependency was originally added as a
    workaround. The pki-core package already requires a newer version of JSS.
    
    Fixes: https://pagure.io/freeipa/issue/7654
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>