9845cd63 broke configuring a cache store like so:

    config.cache_store = :redis_cache_store, config_for("redis/cache")

Rails::Application#config_for returns an ActiveSupport::OrderedOptions. By default, the Array#extract_options! core extension won't extract instances of Hash subclasses. Add ActiveSupport::OrderedOptions#extractable_options? and have it return true to fix.