Eliminate the last warning for redis wrapper

config/application.rb

@@ -6,6 +6,7 @@ Bundler.require(:default, Rails.env)
 
 module Gitlab
   class Application < Rails::Application
+    require_dependency Rails.root.join('lib/gitlab/redis/wrapper')
     require_dependency Rails.root.join('lib/gitlab/redis/cache')
     require_dependency Rails.root.join('lib/gitlab/redis/queues')
     require_dependency Rails.root.join('lib/gitlab/redis/shared_state')

lib/gitlab/redis/cache.rb

 # please require all dependencies below:
-require_relative 'wrapper' unless defined?(::Gitlab::Redis::Wrapper)
+require_relative 'wrapper' unless defined?(::Rails) && ::Rails.root.present?
 
 module Gitlab
   module Redis