[gtk/matthiasc/for-master: 3/6] print-editor: Fix a critical

[Matthias Clasen <matthiasc src gnome org>]

commit f239d26c00294f21fc789802d92a2653b13d8ec9
Author: Matthias Clasen <mclasen redhat com>
Date:   Sun May 10 12:53:37 2020 -0400

    print-editor: Fix a critical
    
    GtkWindow is no longer a container, so don't call
    gtk_container_add on it.

 tests/print-editor.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tests/print-editor.c b/tests/print-editor.c
index a0a8fde4ee..646f3fe93f 100644
--- a/tests/print-editor.c
+++ b/tests/print-editor.c
@@ -748,7 +748,7 @@ activate (GApplication *app)
   update_title (GTK_WINDOW (main_window));
 
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
-  gtk_container_add (GTK_CONTAINER (main_window), box);
+  gtk_window_set_child (GTK_WINDOW (main_window), box);
 
   /* Create document  */
   sw = gtk_scrolled_window_new (NULL, NULL);