[webkit-qt] qt5 version updated for bot / development

[Andras Becsi]

Hi all,

The update this week was a bit delayed, because of changes in Qt5
which resulted in an infinite loop in MiniBrowser's touch mocking
code.
A temporal fix is already uploaded to the bug report:
https://bugs.webkit.org/show_bug.cgi?id=76657 which disables the Qt
touch->mouse synthesis.
We can enable the functionality again if the needed changes land in Qt.

I also prepared a patch which removes the usage of
QWindowSystemInterface::handleMouseEvent, thus if we rather decide not
to use this function, the change can also be landed on Monday.

Thanks for your patience,

/Andras