[kwineffects] Fix wrong object being passed as a QQuickItem* context
Without this patch the following warning is issued: Could not convert argument 1 at onTriggered@file:///usr/share/kpackage/kcms/kcm_kwin_effects/contents/ui/Effect.qml:129 onClicked@file:///usr/lib/qml/org/kde/kirigami.2/templates/SwipeListItem.qml:485 Passing incompatible arguments to C++ functions from JavaScript is dangerous and deprecated. This will throw a JavaScript TypeError in future releases of Qt!