remove unused import

Author: Richard Jones

roundup/mailgw.py

@@ -79,7 +79,7 @@ class node. Any parts of other types are each stored in separate files
 
 import string, re, os, mimetools, cStringIO, smtplib, socket, binascii, quopri
 import time, random, sys, logging
-import traceback, MimeWriter, rfc822
+import traceback, rfc822
 
 from email.Header import decode_header