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
Fix the markdown tables introduced by https://gitlab.com/gitlab-org/gitlab-ce/commit/7cb907cc77f5b7fdc4a5b2acc094e1fa3b3b9f92