[gtkmm-documentation/gmenu] Correct a typo but it still does not work.

[Murray Cumming <murrayc src gnome org>]

commit 44513f42b184783a12cc40b40bf07697b37e5c2b
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Jul 23 11:35:29 2013 +0200

    Correct a typo but it still does not work.

 examples/book/menus/popup/examplewindow.cc |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/examples/book/menus/popup/examplewindow.cc b/examples/book/menus/popup/examplewindow.cc
index 1c20293..ebe17a5 100644
--- a/examples/book/menus/popup/examplewindow.cc
+++ b/examples/book/menus/popup/examplewindow.cc
@@ -50,13 +50,13 @@ ExampleWindow::ExampleWindow()
   m_refActionGroup->add_action("edit",
     sigc::mem_fun(*this, &ExampleWindow::on_menu_file_popup_generic));
 
-  m_refActionGroup->add_action("edit", //TODO: How to specify "<control>P" as an accelerator. 
+  m_refActionGroup->add_action("process", //TODO: How to specify "<control>P" as an accelerator. 
     sigc::mem_fun(*this, &ExampleWindow::on_menu_file_popup_generic));
 
   m_refActionGroup->add_action("remove",
     sigc::mem_fun(*this, &ExampleWindow::on_menu_file_popup_generic));
 
-  insert_action_group("menu-examplepopup", m_refActionGroup);
+  insert_action_group("examplepopup", m_refActionGroup);
 
 
   m_refBuilder = Gtk::Builder::create();