[easytag] Hide help contents menuitem on Windows

[David King <davidk src gnome org>]

commit 33493b81c5de9f340702b4a10233498d6ff6f307
Author: David King <amigadave amigadave com>
Date:   Fri Apr 11 23:42:14 2014 +0100

    Hide help contents menuitem on Windows
    
    Until Yelp runs on Windows, or the Mallard help is on help.gnome.org,
    this will remain hidden.

 src/ui_manager.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/ui_manager.h b/src/ui_manager.h
index 8a064c6..c3d5454 100644
--- a/src/ui_manager.h
+++ b/src/ui_manager.h
@@ -177,7 +177,9 @@ static const gchar *ui_xml =
 "    </menu>"
 
 "    <menu action='HelpMenu'>"
+#ifndef G_OS_WIN32
 "      <menuitem action='HelpContents' />"
+#endif /* !G_OS_WIN32 */
 "      <menuitem action='About' />"
 "    </menu>"