Add options to allow ticket caching
    
    This new option (planned to land in gssproxy 0.7) we cache the ldap
    ticket properly and avoid a ticket lookup to the KDC on each and every
    ldap connection. (Also requires krb5 libs 1.15.1 to benefit from caching).
    
    Ticket: https://pagure.io/freeipa/issue/6771
    
    Signed-off-by: Simo Sorce <simo@redhat.com>
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>