kcmkwin/scripts: fix a warning
Summary:
Prevents warnings such as :
org.kde.kcoreaddons: Expected JSON property "X-KWin-Exclude-Listing" to be a single string. but it is a bool
Reviewers: KWin, ervin, bport, cross, hchain, zzag
Reviewed By: KWin, zzag
Subscribers: zzag, kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D28018