Debugger: Make QImage dumper work with release versions

This accidentally also allows non-debug Qt users to reproduce the
http://blog.qt.digia.com/blog/2010/04/22/peek-and-poke-vol-3/


smiley drawing.

Change-Id: Ica436f55494d012d5516ef9d00d6310f2ac2d4ee
Reviewed-by: hjk <hjk121@nokiamail.com>