[WebProfiler] Tweaked ajax requests toolbar css reset

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #12139 (not sure)
| License       | MIT
| Doc PR        | -

Before:
![screenshot from 2014-12-08 14 52 42](https://cloud.githubusercontent.com/assets/162986/5340221/7b3f1716-7eea-11e4-81c7-f46768736289.png)

After:
![screenshot from 2014-12-08 15 14 35](https://cloud.githubusercontent.com/assets/162986/5340443/fbfb3d1a-7eec-11e4-8960-9990937a49a1.png)