dwellClick: Reindent modes map

Using multiple spaces after property names in order to align the
values isn't something we do elsewhere.

Instead, align the values by using a fixed 4-space indent as preferred
by gjs nowadays.

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

js/ui/status/dwellClick.js

@@ -27,7 +27,7 @@ const DWELL_CLICK_MODES = {
         name: _("Secondary Click"),
         icon: 'pointer-secondary-click-symbolic',
         type: Clutter.PointerA11yDwellClickType.SECONDARY
-               },
+    }
 };
 
 var DwellClickIndicator = GObject.registerClass(