fix font weight of project feature settings

## What does this MR do?
Fixes font weight for project feature settings

## Screenshots (if relevant)
Before:
![Screen_Shot_2016-10-14_at_9.49.06_AM](/uploads/76e1f91cd8f6fcf9197a51215b497e4a/Screen_Shot_2016-10-14_at_9.49.06_AM.png)

After:
![Screen_Shot_2016-10-14_at_11.43.44_AM](/uploads/ecb378400d787c50dba2c3833bb72964/Screen_Shot_2016-10-14_at_11.43.44_AM.png)

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if it does - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
https://gitlab.com/gitlab-org/gitlab-ce/issues/19734#note_16964612

See merge request !6902