Check valid before/after of external certs
verify_server_cert_validity() and verify_ca_cert_validity() now check
the validity time range of external certificates. The check fails if the
certificate is not valid yet or will expire in less than an hour.
Fixes: https://pagure.io/freeipa/issue/8142
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>