Antialiasing of fonts was causing two tests that relied on finding
at least a certain number of pixels of certain color to find one or two
too few pixels of that color and thus fail.
Fixed by increasing the amount of text displayed to make sure enough
pixels of correct color would be present.
Also removing the test insignification, as the test will now
pass completely when run under Windows Classic theme, which CI uses.
Task-number: QTBUG-24323
Change-Id: Ic0b614d33e4e4f5df18d53cb72a05db5d8b6b5e7
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>