Squish: Temporary fix for tst_installed_languages

b748c1b3d2d9ec15aa1ca8711b9a7da4d6dcd00d solved the issue for
Qt Creator running in English only. This test starts Qt Creator
with different language settings, so the app won't close properly.

Change-Id: I63b3b6c4125dc0173c4fd3b4d54c48a0d1dd9687
Reviewed-by: Robert Loehning <robert.loehning@digia.com>