Revert "Improve partial maximization strings"

Summary:
This reverts commit 45bf53ad.

We cannot change config values for existing users since it will break
their installations.

Reviewers: #kwin, davidedmundson

Reviewed By: #kwin, davidedmundson

Subscribers: davidedmundson, bshah, broulik, kwin

Tags: #kwin

Differential Revision: https://phabricator.kde.org/D29736