Repaint QProgressBar when minimum or maximum changed

Repaint QProgressBar when minimum or maximum changed

The implementation of QProgressBar::setMinimum and setMaximum did not
repaint the widget. This caused the widget to be shown incorrectly in
case you call setMinimum or setMaximum but not setValue.

Task-number: QTBUG-22121
(cherry picked from commit b1998f4f59c3b10700963b2d13a17a0cc77ef665)

Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>
Change-Id: I331d37ab4451d9e096cdf91a9e0a0286bc3cdffb
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>