Only activate kded Appmenu signals if menus are in the window decoration
Summary:
The Appmenu applet doesn't use the AppMenu module, and it interferes
with the applet.
Test Plan:
Set menus to in decoration
Pressed alt+f, it appeared
Changed it to be in the applet
pressed alt+f, nothing happened
Reviewers: Plasma, broulik
Reviewed By: Plasma, broulik
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D4833