Drop EffectsHandler::effectsConfig
Summary:
The effectsConfig is no longer used by any Effect. ScriptedEffects use
KWin's KSharedConfigPtr and the builtin effects all have a kcfg with
kwinrc being hard coded.
The effectsConfig had the big disadvantage that it hardcoded kwinrc
while the rest of kwin uses a KSharedConfigPtr which might not point to
kwinrc.
Subscribers: plasma-devel, kwin
Tags: KWin
Differential Revision: https://phabricator.kde.org/D3384