[gnome-shell] panel: Remove left-over Gtk.Settings

[Florian Müllner <fmuellner src gnome org>]

commit 9f8edd980c241500990a535ebf00f49455f65639
Author: Florian Müllner <fmuellner gnome org>
Date:   Thu Apr 4 14:29:30 2019 +0200

    panel: Remove left-over Gtk.Settings
    
    It has been unused since commit c334aa2a4c.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/481

 js/ui/panel.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)
---
diff --git a/js/ui/panel.js b/js/ui/panel.js
index 0f052d3e8..36e16d3c2 100644
--- a/js/ui/panel.js
+++ b/js/ui/panel.js
@@ -1,6 +1,6 @@
 // -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
 
-const { Atk, Clutter, Gio, GLib, GObject, Gtk, Meta, Shell, St } = imports.gi;
+const { Atk, Clutter, Gio, GLib, GObject, Meta, Shell, St } = imports.gi;
 const Cairo = imports.cairo;
 const Mainloop = imports.mainloop;
 
@@ -201,7 +201,6 @@ var AppMenuButton = GObject.registerClass({
         this._startingApps = [];
 
         this._menuManager = panel.menuManager;
-        this._gtkSettings = Gtk.Settings.get_default();
         this._targetApp = null;
         this._busyNotifyId = 0;