dialog: Remove icons from dialogs

According to the new mockups, remove the icon from MessageDialogContent

See https://gitlab.gnome.org/GNOME/gnome-shell/issues/1343

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/886

js/ui/inhibitShortcutsDialog.js

@@ -79,9 +79,8 @@ var InhibitShortcutsDialog = GObject.registerClass({
         let title = name
             ? _("%s wants to inhibit shortcuts").format(name)
             : _("Application wants to inhibit shortcuts");
-        let icon = new Gio.ThemedIcon({ name: 'dialog-warning-symbolic' });
 
-        let contentParams = { icon, title };
+        let contentParams = { title };
 
         let restoreAccel = this._getRestoreAccel();
         if (restoreAccel) {