[gtkmm-documentation] Fixed typo in string

[Daniel Mustieles GarcÃa <dmustieles src gnome org>]

commit b04dc0296a61e1af728a5631b801525d8eb0abaa
Author: Daniel Mustieles <daniel mustieles gmail com>
Date:   Mon Apr 2 11:36:51 2012 +0200

    Fixed typo in string

 docs/tutorial/C/gtkmm-tutorial-in.xml |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/docs/tutorial/C/gtkmm-tutorial-in.xml b/docs/tutorial/C/gtkmm-tutorial-in.xml
index b4ff15d..65d56f3 100644
--- a/docs/tutorial/C/gtkmm-tutorial-in.xml
+++ b/docs/tutorial/C/gtkmm-tutorial-in.xml
@@ -3402,7 +3402,7 @@ Then, to add a widget at that position, use
 <para>
 There are specific APIs for Menus and toolbars, but you should usually deal
 with them together, using the <classname>UIManager</classname> to define
-<classname>Action</classname>s which you can then arrange in menu and toolbars.
+<classname>Action</classname>s which you can then arrange in menus and toolbars.
 In this way you can handle activation of the action instead of responding to
 the menu and toolbar items separately. And you can enable or disable both the
 menu and toolbar item via the action.