Project member pagination is broken when sorting by max role
If you visit a project members page, then sort by "access level, descending", there appears to be a problem with the db query or the pagination. Members will often be repeated on multiple pages, and the order seems inconsistent. For instance, in `www-gitlab-com`'s [project member page](https://gitlab.com/gitlab-com/www-gitlab-com/project_members?sort=access_level_desc), Sid appears on pages 3, 4, and 5: | page 3 | page 4 | page 5 | |-----|-----|-----| | ![project-members-3](/uploads/6d1a219762704efa6fc5d3d12102276d/project-members-3.png) | ![project-members-4](/uploads/a6dd019dfa2b11db83df4bb9372beff5/project-members-4.png) | ![project-members-5](/uploads/2e1ff1925c559fdfd33af577c3d1567d/project-members-5.png) | /cc @jeremy
issue