Bump query guide to latest version

guides/source/active_record_querying.textile

@@ -12,8 +12,6 @@ This guide covers different ways to retrieve data from the database using Active
 
 endprologue.
 
-WARNING. This Guide is based on Rails 3.0. Some of the code shown here will not work in other versions of Rails.
-
 If you're used to using raw SQL to find database records, then you will generally find that there are better ways to carry out the same operations in Rails. Active Record insulates you from the need to use SQL in most cases.
 
 Code examples throughout this guide will refer to one or more of the following models: