ui: route-search - transparency issue on Chrome 56

[SuperITMan]

I'm submitting a...

[X] Regression (a behavior that used to work and stopped working in a new release)
[X] Bug report  
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead see https://github.com/NationalBankBelgium/stark/blob/master/CONTRIBUTING.md#got-a-question-or-problem

Current behavior

On Chrome 56, when opening the search-route, there is an unwanted transparency.

In stark 10.0.0-beta.4 it was working correctly.

Expected behavior

The background of the route-search should be blank instead of transparent.

Minimal reproduction of the problem with instructions

Open showcase on Chrome v56 or IE 11

Environment

Angular version: X.Y.Z
Stark version: 10.0.0-beta.5


Browser:
- [X] Chrome (desktop) version 56
- [ ] Chrome (Android) version XX
- [ ] Chrome (iOS) version XX
- [ ] Firefox version XX
- [ ] Safari (desktop) version XX
- [ ] Safari (iOS) version XX
- [X] IE version 11
- [X] Edge version 41.16299.820.0
 
For Tooling issues:
- Node version: XX  
- Platform:  

Others:

[carlo-nomes]

Also the border on the references