Steps to reproduce:
1) Start Test Studio and try to connect to a TFS on the cloud project
2) You will be prompted to enter your credentials in a separate screen
3) After you've entered the username/password you can login
4) Try to connect to a different cloud project URL
Expected: you get the separate screen again prompting you for credentials
Actually: you get an error message that you don't have rights to access this project. This is because the credentials are not cached and there's no way to remove this caching