[gtkmm] Add a missing include to enums.ccg.

[Kjell Ahlstedt <kjellahl src gnome org>]

commit ca308c98e8caeda361d0e5ad304e349cf2ecf27f
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Wed Jul 10 15:06:45 2013 +0200

    Add a missing include to enums.ccg.
    
    * gtk/src/enums.ccg: Add #include <gtkmm/settings.h>.

 gtk/src/enums.ccg |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/gtk/src/enums.ccg b/gtk/src/enums.ccg
index 2546fe5..af2a8a6 100644
--- a/gtk/src/enums.ccg
+++ b/gtk/src/enums.ccg
@@ -17,6 +17,7 @@
  */
 
 #include <gtkmm/enums.h>
+#include <gtkmm/settings.h>
 
 // static
 GType Glib::Value<Gtk::IconSize>::value_type()