Character: Don't create QChar out of bounds.
An assert was added for this in Qt 6 [1].
[1] https://code.qt.io/cgit/qt/qtbase.git/commit/?id=915be6606ead25f4fbbbcb2687b33cf22a955177
During plasmashell startup repeatedly hit this on character 128444, whatever that is.
Edited by Kai Uwe Broulik