Add a note about autoloading being disabled in production env in upgrade guide [ci skip]

- Also to_time_preserves_timezone config should be false for older apps getting upgraded to Rails 5 [ci skip]

guides/source/configuring.md

@@ -94,7 +94,7 @@ application. Accepts a valid week day symbol (e.g. `:monday`).
 
 * `config.eager_load_paths` accepts an array of paths from which Rails will eager load on boot if cache classes is enabled. Defaults to every folder in the `app` directory of the application.
 
-* `config.enable_dependency_loading`: when true, enables autoload loading, even if the application is eager loaded and `config.cache_classes` is set as true. Defaults to false.
+* `config.enable_dependency_loading`: when true, enables autoloading, even if the application is eager loaded and `config.cache_classes` is set as true. Defaults to false.
 
 * `config.encoding` sets up the application-wide encoding. Defaults to UTF-8.
 

guides/source/upgrading_ruby_on_rails.md

@@ -145,6 +145,12 @@ your Gemfile.
 If you are using Rspec for testing please see the extra configuration required in the gem's
 documentation.
 
+### Autoloading is disabled in production environment
+
+Autoloading of classes is now disabled in production environment by default. If your code
+is dependent on autoloading in production, then you can opt out by setting
+`Rails.application.config.enable_dependency_loading` to true.
+
 ### XML Serialization
 
 `ActiveModel::Serializers::Xml` has been extracted from Rails to the `activemodel-serializers-xml`
@@ -293,7 +299,7 @@ Set the following in your config to enable HSTS when using subdomains.
 
 When using Ruby 2.4 you can preserve the timezone of the receiver when calling `to_time`.
 
-    ActiveSupport.to_time_preserves_timezone = <%= options[:update] ? false : true %>
+    ActiveSupport.to_time_preserves_timezone = false
 
 Upgrading from Rails 4.1 to Rails 4.2
 -------------------------------------