add missed attribute `email_subject_suffix`
attribute email_subject_suffix
was added in gitlab-org/gitlab-ce!6172
but I didn't noticed that we must add it here too.
So it caused this attribute doesn't work in Omnibus package installation
V8.13
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
attribute email_subject_suffix
was added in gitlab-org/gitlab-ce!6172
but I didn't noticed that we must add it here too.
So it caused this attribute doesn't work in Omnibus package installation
V8.13