Remove unneeded import.

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@19170 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/CMFActivity/ActivityBuffer.py

@@ -26,7 +26,6 @@
 from Shared.DC.ZRDB.TM import TM
 from zLOG import LOG, ERROR, INFO
 import sys
-import threading
 
 try:
   from transaction import get as get_transaction