[gtkmm] Remove Gtk::MenuButton::property_align_widget()

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 21b2551cb9045b925fc90ba81e3b55009c112d25
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Mon Aug 10 13:51:41 2020 +0200

    Remove Gtk::MenuButton::property_align_widget()
    
    It has been removed from gtk.

 gtk/src/gtk_extra_objects.defs | 6 ++++++
 gtk/src/menubutton.hg          | 1 -
 2 files changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/gtk/src/gtk_extra_objects.defs b/gtk/src/gtk_extra_objects.defs
index 76815b18..538c1eba 100644
--- a/gtk/src/gtk_extra_objects.defs
+++ b/gtk/src/gtk_extra_objects.defs
@@ -138,6 +138,12 @@
   (gtype-id "GTK_TYPE_DROP_TARGET")
 )
 
+(define-object DropTargetAsync
+  (in-module "Gtk")
+  (c-name "GtkDropTargetAsync")
+  (gtype-id "GTK_TYPE_DROP_TARGET_ASYNC")
+)
+
 (define-object Editable
   (in-module "Gtk")
   (c-name "GtkEditable")
diff --git a/gtk/src/menubutton.hg b/gtk/src/menubutton.hg
index 4625c924..ca705ea7 100644
--- a/gtk/src/menubutton.hg
+++ b/gtk/src/menubutton.hg
@@ -114,7 +114,6 @@ public:
   void unset_create_popup_func();
 
   _WRAP_PROPERTY("menu-model", Glib::RefPtr<Gio::MenuModel>)
-  _WRAP_PROPERTY("align-widget", Widget*)
   _WRAP_PROPERTY("direction", ArrowType)
   _WRAP_PROPERTY("popover", Popover*)
   _WRAP_PROPERTY("icon-name", Glib::ustring)