Less redundant freeing of resources on redirects

With 495646bb6a the double flush is no longer
needed.

requests/models.py

@@ -210,6 +210,8 @@ class Request(object):
             while (('location' in r.headers) and
                    ((r.status_code is codes.see_other) or (self.allow_redirects))):
 
+                r.content  # Consume socket so it can be released
+
                 if not len(history) < self.config.get('max_redirects'):
                     raise TooManyRedirects()