[gtk: 1/3] gtk-demo: Fix expander demo

[Matthias Clasen <matthiasc src gnome org>]

commit fede7cd81c623a2a18e7a77fa0f21b23e10e00d6
Author: Alexander Larsson <alexl redhat com>
Date:   Wed May 13 10:50:41 2020 +0200

    gtk-demo: Fix expander demo
    
    GtkExpander is not a GtkBox anymore, so use the new gtk_expander_set_child()
    API.

 demos/gtk-demo/expander.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/demos/gtk-demo/expander.c b/demos/gtk-demo/expander.c
index 46ccff1833..6d4583dbff 100644
--- a/demos/gtk-demo/expander.c
+++ b/demos/gtk-demo/expander.c
@@ -79,7 +79,7 @@ do_expander (GtkWidget *do_widget)
                                 "innuendo, just to make you scroll down or "
                                 "resize the window. Do it already !", -1);
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), tv);
-      gtk_box_append (GTK_BOX (expander), sw);
+      gtk_expander_set_child (GTK_EXPANDER (expander), sw);
       gtk_box_append (GTK_BOX (area), expander);
       g_signal_connect (expander, "notify::expanded",
                         G_CALLBACK (expander_cb), window);