Qnx: Fix broken configuration manager test

The change 0e67b293b7eaf0bff055d1587577c453397ba153
broke the configuration manager test since
the manager gets now instantiated when loading the plugin
whereas the test assumes that it would be instantiated
when ::instance() is called the first time.

Change-Id: I8f873fa56305da37590e401e8cfb98b8c92fe89d
Reviewed-by: Christian Stenger <christian.stenger@digia.com>
Reviewed-by: Sergio Ahumada <sahumada@blackberry.com>