Debugger: Fix handling of ? in dumper test

Normally, we use '?' as an optional Qt namespace qualification.
This clashes with the use of ? in a regexp type expression.
Re-order checks to avoid the clash.

Change-Id: I4a8aee0174f4f3d21bec624919856623808becb1
Reviewed-by: Christian Stenger <christian.stenger@theqtcompany.com>