Merge pull request rails#25731 from chen7897499/fix_typo

Fix typo: caches_pages to caches_page. [ci skip]

Author: senny

guides/source/upgrading_ruby_on_rails.md

@@ -1185,7 +1185,7 @@ Please read [Pull Request #9978](https://github.com/rails/rails/pull/9978) for d
 
 * Rails 4.0 has deprecated `ActionController::Base.page_cache_extension` option. Use `ActionController::Base.default_static_extension` instead.
 
-* Rails 4.0 has removed Action and Page caching from Action Pack. You will need to add the `actionpack-action_caching` gem in order to use `caches_action` and the `actionpack-page_caching` to use `caches_pages` in your controllers.
+* Rails 4.0 has removed Action and Page caching from Action Pack. You will need to add the `actionpack-action_caching` gem in order to use `caches_action` and the `actionpack-page_caching` to use `caches_page` in your controllers.
 
 * Rails 4.0 has removed the XML parameters parser. You will need to add the `actionpack-xml_parser` gem if you require this feature.