st: Remove StBin's align properties

They are now completely unused, so remove them and stop the confusing
shadowing of ClutterActor's own x/y-align properties.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/803

js/ui/popupMenu.js

@@ -340,9 +340,9 @@ var PopupSwitchMenuItem = GObject.registerClass({
         this.add_child(this.label);
 
         this._statusBin = new St.Bin({
+            x_align: Clutter.ActorAlign.END,
             x_expand: true,
         });
-        this._statusBin.set_x_align(Clutter.ActorAlign.END);
         this.add_child(this._statusBin);
 
         this._statusLabel = new St.Label({