CORE-17702
Only show the main dialog pane in the taskbar when executing a Cancel dialog.
- Improve previous msi/dialog.c patch to match current Wine code.
- Remove #ifdef's for already committed Wine Code.
In effect, importing Wine's commit 4b88e290521ef9fde9290c9bcbae7420966a6f46:
msi: Set dialog as parent in subsequent dialog.
Author: Fabian Maurer <dark.shadow4@web.de>
Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=51576