[REG->5.12] Reopening Quick window on another screen crashes application.

User has found a way to crash application if new window is created, moved to another screen, closed there and tried to reopen.

Support has tested the example and it crashes the app.

Steps to reproduce the crash with the attached example project:
Begin application.
Click the first button
Move the newly created window to a different display
Close it, but with the native "X" in the window Top Right corner.
("Close it" button does not seem to trigger a fatal.)
Click the first button (again)
Note assert

File: kernel\qplatformwindow.cpp
Line: 767
ASSERT: "!d->updateTimer.isActive()" in file kernel\qplatformwindow.cpp, line 767