UI Freeze exception request

[Ara Pulido]

Hello,

We are requesting a UI Freeze exception for Checkbox:

   https://bugs.launchpad.net/ubuntu/+source/checkbox/+bug/957090

The reason is that the welcome tab in the application is pretty much
useless, and it is confusing the users.

Also, it is really bug prone, as trying to start again the test run is
very difficult.

We are just removing the tab, so it shouldn't affect the translations
team (no new strings)

Thanks,
Ara.