Clean up includes
Summary:
- effects.h includes client.h and forward declares Client, both at the same time. Thus, delete the include;
- the blur effect includes effects.h. That, most likely, is a leftover after 3f5bf65a9ec8fa413ca59dd07df267c8b765329c.
Test Plan: Compiles.
Reviewers: KWin, davidedmundson
Reviewed By: KWin, davidedmundson
Subscribers: kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D15191