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/SimpleHTTPServer.py b/Lib/SimpleHTTPServer.py
index 86c669e..a1f25be 100644
--- a/Lib/SimpleHTTPServer.py
+++ b/Lib/SimpleHTTPServer.py
@@ -18,10 +18,7 @@
 import cgi
 import shutil
 import mimetypes
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
+from io import StringIO
 
 
 class SimpleHTTPRequestHandler(BaseHTTPServer.BaseHTTPRequestHandler):