Enable Origin header check in forgery protection

This is the default in Rails 5 applications.

This option is not enabled by default in existing applications because
it would break applications running on several domains and doing POST
requests between them or running a reverse proxy that rewrites the Host
header. Since those aren't our cases, it's safe to enable it.

config/application.rb

@@ -11,7 +11,6 @@ module Consul
     config.load_defaults 5.0
 
     # Overwrite Rails 5.0 defaults and use the options we used in Rails 4
-    config.action_controller.forgery_protection_origin_check = nil
     ActiveSupport.to_time_preserves_timezone = false
     config.active_record.belongs_to_required_by_default = false
     config.ssl_options = {}