cainstance: do not configure renewal guard
    
    Do not configure renewal guard for dogtag-ipa-renew-agent, as it is not
    used in IPA anymore.
    
    https://fedorahosted.org/freeipa/ticket/5959
    
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>