Changing Gerrit username need restart of Creator

1. Open and close the Gerrit dialog.
2. Go to "Tools" -> "Options..." -> "Version Control" -> "Gerrit".
3. Enter a different username and click "OK".
4. Open and close the Gerrit dialog.
5. Show the "Version Control" output view.
   Both times, exactly the same call to ssh was used.

Instead, the second call should have used the new username. It will be used after a restart of Creator.