CPack/NSIS: Fix installer not waiting for uninstaller to finish
!7096 (merged) removed the _?
parameter when calling the uninstaller during installation.
This parameter is however essential for ExecWait to actually wait for
the uninstaller to finish.
Without it, the uninstaller is started in the background and installer
and uninstaller run at the same time.
See https://nsis.sourceforge.io/Docs/Chapter3.html#installerusageuninstaller
Add back the _?
parameter to fix this regression.
Fixes: #24041 (closed)
Topic-rename: cpack-nsis-uninstaller
Edited by Brad King