[gtk+] Plug a memory leak

[Matthias Clasen <matthiasc src gnome org>]

commit 3db98fe23cb1f4a1b44f5eab7d6731634464326a
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Sep 15 10:32:02 2015 -0400

    Plug a memory leak

 demos/gtk-demo/listbox.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/demos/gtk-demo/listbox.c b/demos/gtk-demo/listbox.c
index eeeda5a..ee94d55 100644
--- a/demos/gtk-demo/listbox.c
+++ b/demos/gtk-demo/listbox.c
@@ -358,6 +358,7 @@ do_listbox (GtkWidget *do_widget)
         }
 
       g_strfreev (lines);
+      g_bytes_unref (data);
     }
 
   if (!gtk_widget_get_visible (window))