[glibmm] ActionMap: add_action(): Actually add the action.

[Murray Cumming <murrayc src gnome org>]

commit fc953d619ccb472d0cb0a9b089a5b3abe4baf8fa
Author: Murray Cumming <murrayc murrayc com>
Date:   Tue Jul 23 21:35:06 2013 +0200

    ActionMap: add_action(): Actually add the action.
    
    Thanks to Kjell.

 gio/src/actionmap.ccg |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/gio/src/actionmap.ccg b/gio/src/actionmap.ccg
index 9e3c562..8c651fb 100644
--- a/gio/src/actionmap.ccg
+++ b/gio/src/actionmap.ccg
@@ -27,6 +27,7 @@ Glib::RefPtr<SimpleAction> ActionMap::add_action(const Glib::ustring& name, cons
 {
   Glib::RefPtr<SimpleAction> action = SimpleAction::create(name);
   action->signal_activate().connect(slot);
+  add_action(action);
   return action;
 }