Removed default empty content argument from HttpResponse calls.

tests/test_client_regress/views.py

@@ -21,7 +21,7 @@ def no_template_view(request):
 def staff_only_view(request):
     "A view that can only be visited by staff. Non staff members get an exception"
     if request.user.is_staff:
-        return HttpResponse('')
+        return HttpResponse()
     else:
         raise CustomTestException()