Change some uses of cStringIO.StringIO to io.StringIO.
This is undoubtedly insufficient and in some cases just as broken as before.
diff --git a/Lib/urllib2.py b/Lib/urllib2.py
index a0be039..284c921 100644
--- a/Lib/urllib2.py
+++ b/Lib/urllib2.py
@@ -101,10 +101,7 @@
 import urlparse
 import bisect
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
+from io import StringIO
 
 from urllib import (unwrap, unquote, splittype, splithost, quote,
      addinfourl, splitport, splitgophertype, splitquery,