3.1 Merge Request Diff Comments not shown on Diff

Created by: ConnorDoyle

1. Create a Merge Request
2. View the diff
3. Click the "+" button to add an inline comment.
4. Type some text
5. Click the green "Add Comment" button.
6. Note the comment is not shown on the diff.
7. Click the "Comments" tab.
8. Refresh the page.
9. Note the comment is shown with the MR comments.