Added missing % to format a string.

diff --git a/tornado/web.py b/tornado/web.py
index 12939337e33dc998266e44568ae5c15b6a82af96..ec4b16302fca53fd8ff3033bffe55f1d43ed1d19 100644 (file)
--- a/tornado/web.py
+++ b/tornado/web.py
@@ -313,7 +313,7 @@ class RequestHandler(object):
             try:
                 self._reason = httputil.responses[status_code]
             except KeyError:
-                raise ValueError("unknown status code %d", status_code)
+                raise ValueError("unknown status code %d" % status_code)
 
     def get_status(self):
         """Returns the status code for our response."""