Integration test failing due to license key dialog showing.

PR failure: https://ci.dot.net/job/dotnet_roslyn/job/master/job/windows_debug_vs-integration_prtest/5316/

UI thread is currently doing:

![image](https://user-images.githubusercontent.com/4564579/27005864-e7494e00-4ddb-11e7-94db-cd91c28c9cda.png)

