force styles generation, since we aren't in the normal paperclip path

we are unsetting the attachment_s3_key to avoid an infinite loop, because after the call to reprocess! the object will be saved and the after save will be called, calling the reporcess! again, and this variable is the guard to call the callback.

lib/s3-upnow/paperclip.rb

@@ -52,6 +52,8 @@ def has_attached_file(name, options = {})
           dest_bucket = s3.buckets[s3_upnow_destination_bucket(name)]
           dest_object = dest_bucket.objects[s3_upnow_destination_path(name)]
           dest_object.copy_from(orig_object, acl: s3_upnow_destination_permissions(name))
+          remove_instance_variable("@#{name}_s3_key")
+          s3_upnow_attachment(name).reprocess!
         end
       end
       super(name, options)