Fix markdown table in API Issues docs
What does this MR do?
Fix the markdown tables introduced by https://gitlab.com/gitlab-org/gitlab-ce/commit/7cb907cc77f5b7fdc4a5b2acc094e1fa3b3b9f92
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Fix the markdown tables introduced by https://gitlab.com/gitlab-org/gitlab-ce/commit/7cb907cc77f5b7fdc4a5b2acc094e1fa3b3b9f92