[FIX] remove unused deps

controllers/main.py

@@ -4,7 +4,6 @@ from openerp.http import request
 from werkzeug.wrappers import Response
 from werkzeug.datastructures import Headers
 from datetime import datetime
-from StringIO import StringIO
 from gzip import GzipFile
 from StringIO import StringIO as IO
 import simplejson as json