XMLRPC tests: add new test for ipa dsnrecord-mod $ZONE $RECORD --ttl
The test suite did not have any test for modification of the TTL
of an existing DNS record.
Related: https://pagure.io/freeipa/issue/7982
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>