The choice of whether to show a message again is per message,
so when showing a new message we need to reset the check box
back to its default checked state, otherwise the user might
mistakenly dismiss more than the indented message.
[ChangeLog][Widgets] QErrorMessage will now reset the check
box for showing a message again for each new message shown,
as each individual message has its own suppression state.
Pick-to: 6.5 6.5.0
Change-Id: I86d4bb5eabdb5b7a478c03516108a5edf87fcbe3
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
f2fc2013de