remove unused import

IPython/html/files/handlers.py

@@ -1,57 +1,51 b''
 """Base Tornado handlers for the notebook server."""
 
 # Copyright (c) IPython Development Team.
 # Distributed under the terms of the Modified BSD License.
 
 import logging
 import os
 import mimetypes
 import json
 import base64
 
-try:
-    # py3
-    from http.client import responses
-except ImportError:
-    from httplib import responses
-
 from tornado import web
 
 try:
     from tornado.log import app_log
 except ImportError:
     app_log = logging.getLogger()
 
 from IPython.html.base.handlers import IPythonHandler
 
 class FilesHandler(IPythonHandler):
     """serve files via ContentsManager"""
 
     @web.authenticated
     def get(self, path):
         cm = self.settings['contents_manager']
         if cm.is_hidden(path):
             self.log.info("Refusing to serve hidden file, via 404 Error")
             raise web.HTTPError(404)
 
         path, name = os.path.split(path)
         model = cm.get_model(name, path)
 
         if model['type'] == 'notebook':
             self.set_header('Content-Type', 'application/json')
         else:
             cur_mime = mimetypes.guess_type(name)[0]
             if cur_mime is not None:
                 self.set_header('Content-Type', cur_mime)
         
         self.set_header('Content-Disposition','attachment; filename="%s"' % name)
 
         if model['format'] == 'base64':
             b64_bytes = model['content'].encode('ascii')
             self.write(base64.decodestring(b64_bytes))
         elif model['format'] == 'json':
             self.write(json.dumps(model['content']))
         else:
             self.write(model['content'])
         self.flush()