[gtk+] demos: Remove undefined function call

[Emmanuele Bassi <ebassi src gnome org>]

commit c8b92cb0d2494352bf2558409f3025f0d9d22cf7
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Tue Nov 29 23:29:10 2016 +0000

    demos: Remove undefined function call
    
    The gtk_container_set_border_width() function has been removed from
    the GTK+ 4.x API.

 demos/gtk-demo/tabs.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)
---
diff --git a/demos/gtk-demo/tabs.c b/demos/gtk-demo/tabs.c
index c1b511d..18d15de 100644
--- a/demos/gtk-demo/tabs.c
+++ b/demos/gtk-demo/tabs.c
@@ -27,8 +27,6 @@ do_tabs (GtkWidget *do_widget)
       g_signal_connect (window, "destroy",
                         G_CALLBACK (gtk_widget_destroyed), &window);
 
-      gtk_container_set_border_width (GTK_CONTAINER (window), 0);
-
       view = gtk_text_view_new ();
       gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
       gtk_text_view_set_left_margin (GTK_TEXT_VIEW (view), 20);