wsgi: Do not access sys.stderr .

caucase/wsgi.py

@@ -22,7 +22,6 @@ from __future__ import absolute_import
 import httplib
 import json
 import traceback
-import sys
 from . import utils
 from . import exceptions
 
@@ -191,8 +190,8 @@ class Application(object):
       except exceptions.CertificateAuthorityException, e:
         raise BadRequest(str(e))
       except Exception:
-        print >>sys.stderr, 'Unhandled exception',
-        traceback.print_exc(file=sys.stderr)
+        environ['wsgi.errors'].write('Unhandled exception\n')
+        traceback.print_exc(file=environ['wsgi.errors'])
         raise ApplicationError
     except ApplicationError, e:
       status = e.status