ipa-advise: if p11-kit provides opensc, don't add to NSS db
    
    p11-kit-proxy in newer distributions handles loading the OpenSC
    PKCS#11 library so don't try to add it to the NSS database in
    /etc/pki/nssdb if it is already available in order to avoid a
    potentially confusing error message.
    
    https://pagure.io/freeipa/issue/8934
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>