rake railties:install:migrations respects the order of railties

I have a couple of projects that make use of Rails' engines. There are two engines with migrations, where one engine depends on having a database table created in a migration in another engine. Unfortinately, "railties:install:migrations" task does not respect the order of engines that one can configure via "Rails.application.config.railties_order". This simple commit fixes that by using "ordered_railties" instead of "railties".