makes compare previous version link easily clickable

## What does this MR do?
This MR does a minor fix about `Compare previous link` which is not easily clickable when long commit list are expanded

## Are there points in the code the reviewer needs to double check?
NR
## Why was this MR needed?
For better UX and make browse easy

## Screenshots (if relevant)

**Before:**
![BrRs](/uploads/11e60ef150a9035ae94d6ed69c3038b5/BrRs.gif)

**After**
![2016-11-19_02.02.42](/uploads/961bac1ddcdc4338ac72bc690c52b7f1/2016-11-19_02.02.42.gif)

## Does this MR meet the acceptance criteria?

- [ ] [Changelog entry](https://docs.gitlab.com/ce/development/changelog.html) 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
  - [x] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [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 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?


Closes #24658

See merge request !7587