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/lookingGlass.js

@@ -265,8 +265,8 @@ class ObjLink extends St.Button {
             track_hover: true,
             style_class: 'shell-link',
             label: text,
+            x_align: Clutter.ActorAlign.START,
         });
-        this.set_x_align(Clutter.ActorAlign.START);
         this.get_child().single_line_mode = true;
 
         this._obj = o;