failure to access to login/failure with ActionController::RedirectBackError: No HTTP_REFERER

When I accessed login/failure directly, AsakusaSatellite crashed with following error:

```
ActionController::RedirectBackError: No HTTP_REFERER was set in the request to this action, so redirect_to :back could not be called successfully. If this is a test, make sure to specify request.env["HTTP_REFERER"].
```