runtornado: Don't apply response middleware twice

This was causing us to log some requests twice, and might have more serious
consequences as well.

(imported from commit 0bb2d7207ee3e4e04679215a7f5ae637cd26aa19)

zephyr/management/commands/runtornado.py

@@ -130,11 +130,6 @@ class AsyncDjangoHandler(tornado.web.RequestHandler, base.BaseHandler):
 
             if not response:
                 return
-
-            # Apply response middleware
-            for middleware_method in self._response_middleware:
-                response = middleware_method(request, response)
-            response = self.apply_response_fixes(request, response)
         finally:
             signals.request_finished.send(sender=self.__class__)