sip_session: wait for 2 seconds before printing "stopping the engine"

darcs-hash:20090324135515-b2873-0aad56dbd8031497c676336362b9544cb109047b
fix AttributeError in sip_im_session

darcs-hash:20090324140024-b2873-27264f58f0a49b8b88c813c4e8dcb6c05ed7534b