[gtkmm] Gdk::Window::create_gl_context(): Remove refreturn

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 6ab4fe24158d168ee86342735de27ca82b69a715
Author: Kjell Ahlstedt <kjell ahlstedt bredband net>
Date:   Mon Apr 25 10:19:14 2016 +0200

    Gdk::Window::create_gl_context(): Remove refreturn
    
    gdk_window_create_gl_context() gives the caller a reference. Then refreturn
    in _WRAP_METHOD() will most probably cause a memory leak.

 gdk/src/window.hg |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gdk/src/window.hg b/gdk/src/window.hg
index 9dc10a4..9ec39d5 100644
--- a/gdk/src/window.hg
+++ b/gdk/src/window.hg
@@ -412,7 +412,7 @@ public:
    *
    * @throws GLError On missing GL implementation or extension required for context creation.
    */
-  _WRAP_METHOD(Glib::RefPtr<Gdk::GLContext> create_gl_context(), gdk_window_create_gl_context, refreturn, 
errthrow)
+  _WRAP_METHOD(Glib::RefPtr<Gdk::GLContext> create_gl_context(), gdk_window_create_gl_context, errthrow)
 
   _WRAP_PROPERTY("cursor", Glib::RefPtr<Cursor>)
 };