Project search is not available under window width 992px

Summary

Project search is not available on small screens.

Similar to gitlab-foss#23721 (closed).

Steps to reproduce

1. Visit https://gitlab.com/gitlab-org/gitlab-ce.
2. Resize the browser window to 991 pixels wide or smaller.

What is the current bug behavior?

The search input becomes a link to https://gitlab.com/search (from which you can't search this project unless it's one of your assigned projects).

What is the expected correct behavior?

• If the search icon is clicked, it should scope to the project. Same as if you are searching from a larger screen. E.g. https://gitlab.com/search?project_id=XXX
• The Group and Project filters in the search page should be able to search/show all of the instance's groups and projects.

Screenshots

• Screen_Shot_2017-03-29_at_09.19.32
• Screen_Shot_2017-03-29_at_09.19.41

Output of checks

This bug happens on GitLab.com