[gtk/sorter-constructor-fix-warning] Fix warning in listview_settings demo

[andreas56 <andreasp src gnome org>]

commit 81c835c4185df69596ce248bce8ea7772fe65d49
Author: Andreas Persson <andreasp56 outlook com>
Date:   Tue Sep 8 18:48:54 2020 +0200

    Fix warning in listview_settings demo
    
    Fix a warning introduced when sorter constructors were changed to return
    exact types.

 demos/gtk-demo/listview_settings.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/listview_settings.c b/demos/gtk-demo/listview_settings.c
index 57aa7d576f..57e4797c1a 100644
--- a/demos/gtk-demo/listview_settings.c
+++ b/demos/gtk-demo/listview_settings.c
@@ -417,7 +417,7 @@ do_listview_settings (GtkWidget *do_widget)
       g_object_unref (selection);
 
       name_column = GTK_COLUMN_VIEW_COLUMN (gtk_builder_get_object (builder, "name_column"));
-      sorter = gtk_string_sorter_new (gtk_property_expression_new (SETTINGS_TYPE_KEY, NULL, "name"));
+      sorter = GTK_SORTER (gtk_string_sorter_new (gtk_property_expression_new (SETTINGS_TYPE_KEY, NULL, 
"name")));
       gtk_column_view_column_set_sorter (name_column, sorter);
       g_object_unref (sorter);