Fix eager loading a Rails app with performs in an associated object

ActiveJob::Performs was being included in an after_initialize hook,
which was after the models were loaded, which means that an associated
object that has a `performs` call in it had no `performs` method.

This triggered the method_missing to run and find the `performs` method
on the ActiveRecord model, use that, and then attempt to call my
associated object name on the return value.

Given this code:

class AudioTrack::ListeningPlanDaySyncer < ActiveRecord::AssociatedObject
  performs :sync
end

`performs` didn't exist, so it'd call `AudioTrack.performs :sync`, which
returns :sync_later. Then the method_missing code would attempt to
run `:sync_later.listening_plan_day_syncer` and error.

By moving this on_load hook out of `after_initialize`, I now have a `performs`
method when eager loading.

I think the only reason it was working before is because the models
were being lazy loaded, so I didn't attempt to call `performs` until
long after boot.

lib/active_record/associated_object/railtie.rb

@@ -3,17 +3,17 @@ class ActiveRecord::AssociatedObject::Railtie < Rails::Railtie
     config.after_initialize do
       ActiveRecord::AssociatedObject.include Kredis::Attributes       if defined?(Kredis)
       ActiveRecord::AssociatedObject.include GlobalID::Identification if defined?(GlobalID)
-
-      ActiveSupport.on_load :active_job do
-        require "active_job/performs"
-        ActiveRecord::AssociatedObject.extend ActiveJob::Performs
-      rescue LoadError
-        # We haven't bundled active_job-performs, so we're continuing without it.
-      end
     end
   end
 
   initializer "object_association.setup" do
+    ActiveSupport.on_load :active_job do
+      require "active_job/performs"
+      ActiveRecord::AssociatedObject.extend ActiveJob::Performs
+    rescue LoadError
+      # We haven't bundled active_job-performs, so we're continuing without it.
+    end
+
     ActiveSupport.on_load :active_record do
       require "active_record/associated_object/object_association"
       extend ActiveRecord::AssociatedObject::ObjectAssociation