Add X-Frame-Options and frame-ancestors options
These two options allow preventing clickjacking attacks. They don't allow
open FreeIPA in frame, iframe or object element.
https://fedorahosted.org/freeipa/ticket/4631
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>
Reviewed-By: Simo Sorce <ssorce@redhat.com>