Issue 9568 - Update IPA to IPA migration design doc
The usage for migrating DNS changed. It went from "--skip-dns",
to "--migrate-dns"
Fixes: https://pagure.io/freeipa/issue/9568
Signed-off-by: Mark Reynolds <mreynolds@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>