Even though 'id' attribute is output-only, we should accept xml
files containing it.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1941594
Signed-off-by: Kristina Hanicova <khanicov@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>