'Browse files' button on the commit page is sometimes absent
Zendesk: https://gitlab.zendesk.com/agent/tickets/56330
A customer shared a screenshot and said that sometimes the 'Browse files' button isn't available next to a certain commit. The interesting thing is I don't see any conditional in the view that would account for this - https://gitlab.com/gitlab-org/gitlab-ce/blob/master/app/views/projects/commit/_commit_box.html.haml#L24. Any ideas why we would show the button in some scenario?