Add a compatibility workaround for WooCommerce 2.2.1+.

Summary: With AME active, an unusable WooCommerce -> WooCommerce menu item would show up. Now AME removes it. See code comments for more details.

git-svn-id: https://plugins.svn.wordpress.org/admin-menu-editor/trunk@987071 b8457f37-d9ea-0310-8a92-e5e31aec5664