Fix up typo.

Author: Flameeyes

cachecontrol/controller.py

@@ -312,7 +312,7 @@ def cache_response(self, request, response, body=None, status_codes=None):
         # Add to the cache any 301s. We do this before looking that
         # the Date headers.
         elif response.status == 301:
-            logger.debug("Caching permanant redirect")
+            logger.debug("Caching permanent redirect")
             self.cache.set(cache_url, self.serializer.dumps(request, response))
 
         # Add to the cache if the response headers demand it. If there