(ITS#8035) syncrepl consumer memleak

[hyc@openldap.org]

Full_Name: Howard Chu
Version: HEAD/RR24
OS: 
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (180.180.122.131)
Submitted by: hyc


The consumer can leak a cookie if it gets an error and retries the sync session
and it was the initial refresh of the DB, i.e., it had no valid cookie or
contextCSN yet.

It can also leak an entry if it's in Persist phase and while attempting to add
an entry it gets a NO_SUCH_OBJECT error.

Fix coming shortly.