[kcms/launch] Avoid infinite loop in button handling
Summary:
When visiting Applications / Launch Feedback the star, indicating a edit
on this page, begin to flicker.
QQC2 allows us to fix it properly.
BUG: 403950
Test Plan: Made some changes
Reviewers: Plasma, broulik
Reviewed By: Plasma, broulik
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D18748