folder.IMAP: Don't import copy

It is not needed. list(ALIST) will create a new copy of the list just
fine.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>

offlineimap/folder/IMAP.py

@@ -21,7 +21,6 @@ import random
 import binascii
 import re
 import time
-from copy import copy
 from Base import BaseFolder
 from offlineimap import imaputil, imaplibutil, OfflineImapError
 try: # python 2.6 has set() built in
@@ -653,7 +652,7 @@ class IMAPFolder(BaseFolder):
         # Some IMAP servers do not always return a result.  Therefore,
         # only update the ones that it talks about, and manually fix
         # the others.
-        needupdate = copy(uidlist)
+        needupdate = list(uidlist)
         for result in r:
             if result == None:
                 # Compensate for servers that don't return anything from