style: Fix indentation errors

While we have some style inconsistencies - mostly regarding split lines,
i.e. aligning to the first arguments vs. a four-space indent - there are
a couple of places where the spacing is simply wrong. Fix those.

Spotted by eslint.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/608

js/ui/overviewControls.js

@@ -410,7 +410,7 @@ var ControlsManager = class {
                                      x_expand: true, y_expand: true,
                                      clip_to_allocation: true });
         this._group = new St.BoxLayout({ name: 'overview-group',
-                                        x_expand: true, y_expand: true });
+                                         x_expand: true, y_expand: true });
         this.actor.add_actor(this._group);
 
         this.actor.add_actor(this._dashSlider.actor);