Merge branch '18463-search-form-padding-is-too-damn-high' into 'master'

Fixed search form padding

## What does this MR do?

Corrects the padding of the search form.

## Are there points in the code the reviewer needs to double check?

Ney.

## Why was this MR needed?

UX

## What are the relevant issue numbers?

Closes #18463.

## Screenshots (if relevant)

![Screen_Shot_2016-06-10_at_14.07.32](/uploads/e4d127c66cf7fa3286279367d6e4ea7c/Screen_Shot_2016-06-10_at_14.07.32.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
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !4591

app/assets/stylesheets/framework/nav.scss

@@ -171,7 +171,6 @@
     > form {
       display: inline-block;
       margin-top: -1px;
-      margin-bottom: 12px;
     }
 
     .icon-label {