Bug 467558

If you play a video (to review the subtitle for example) in fullscreen mode, and then go out of fullscreen, all the app window become black and it somehow crashes.

Note: I'm using subtitlecomposer 0.7.1-6 on arch (latest version compiled from AUR)

Logs when it happens:
```
OpenGL version:  4.6 (Compatibility Profile) Mesa 22.3.6
GLSL version:  4.60
Color range: tv(1); primaries: bt709(1); xfer: bt709(1); space: bt709(1); depth: 8
OpenGL version:  4.6 (Compatibility Profile) Mesa 22.3.6
GLSL version:  4.60
qt.qpa.wayland: Wayland does not support QWindow::requestActivate()
QObject::killTimer(): Error: timer id 128 is not valid for object 0x560bd03fbe90 (AttachableWidget, ), timer has not been killed
OpenGL version:  4.6 (Compatibility Profile) Mesa 22.3.6
GLSL version:  4.60

```

SOFTWARE/OS VERSIONS

KDE Plasma Version: 5.27.3
KDE Frameworks Version: 5.104.0
Qt Version: 5.15.8
Kernel Version: 6.2.7-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 7.6 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 620