Fix failing autotest
Summary:
KWindowInfoX11Test fails because some parts of QXcbWindow were changed in
Qt 5.12.X:
- Since Qt 5.12.1, QXcbWindow sets WM_CLIENT_LEADER property for all clients;
- Since Qt 5.12.0, QXcbWindow sets WM_CLIENT_MACHINE property.
Reviewers: KWin, Frameworks, davidedmundson
Reviewed By: KWin, davidedmundson
Subscribers: kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D22685