[gtk+] gtk-demo: fix colorchooser example

[Matthias Clasen <matthiasc src gnome org>]

commit a66147dc82b63a664d60665badcbfda542d202cd
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Dec 3 23:30:52 2013 -0500

    gtk-demo: fix colorchooser example
    
    A nested dialog on top of a modal dialog must itself be modal,
    otherwise it doesn't get any input.

 demos/gtk-demo/colorsel.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/demos/gtk-demo/colorsel.c b/demos/gtk-demo/colorsel.c
index 73042f9..566af21 100644
--- a/demos/gtk-demo/colorsel.c
+++ b/demos/gtk-demo/colorsel.c
@@ -52,6 +52,7 @@ change_color_callback (GtkWidget *button,
   GtkWidget *dialog;
 
   dialog = gtk_color_chooser_dialog_new ("Changing color", GTK_WINDOW (window));
+  gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
   gtk_color_chooser_set_rgba (GTK_COLOR_CHOOSER (dialog), &color);
 
   g_signal_connect (dialog,