Update tst_QTextEdit::fullWidthSelection

Update tst_QTextEdit::fullWidthSelection

Since we would add 1 to the height of script lines in the layout before
and there was no compensation for this in the box font engine, which is
used by this test, the selection rect in the test images was one pixel too
high. Now that the +1 has been removed from the height, the images have to
be updated.

Change-Id: Ic9ea0ace6b61be496846c7f757ae309756cd9f5f
Reviewed-by: Bradley T. Hughes <bradley.hughes@nokia.com>