examples/qtbase/widgets/calendarwidget example does not reformat correctly

Steps to reproduce:

1. Run calendarwidget example
2. Navigate to May on the calendar
3. Check "May 1 in red" - colour changes to red
4. Uncheck "May 1 in red" - colour is still red
5. Check "First Friday in blue" - colour changes to blue
6. Uncheck "First Friday in blue" - colour is still blue