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>

src/plugins/debugger/imageviewer.cpp

@@ -69,6 +69,7 @@ void ImageWidget::setImage(const QImage &image)
 {
     setFixedSize(image.size() + QSize(2, 2));
     m_image = image;
+    update();
 }
 
 void ImageWidget::mousePressEvent(QMouseEvent *ev)