Filter configure action out of overflow menu correctly

This code was trying to filter out the configure action but failing
because it was comparing a QMenuItem to a QAction. We need to compare
the QMenuItem's internal QAction in order for the configure action to
ever match.

Companion to 827afc3fc276d0d73b4e4d2f08e26c24a3e6ea71 in
plasma-workspace.

src/declarativeimports/plasmaextracomponents/qml/BasicPlasmoidHeading.qml

@@ -112,7 +112,7 @@ PlasmoidHeading {
                     action: modelData
                 }
                 onObjectAdded: {
-                    if (object !== plasmoid.action("configure")) {
+                    if (object.action !== plasmoid.action("configure")) {
                         configMenu.addMenuItem(object);
                     }
                 }