(ITS#4595) accesslog purge bug with cn=config

[hyc@OpenLDAP.org]

Full_Name: Howard Chu
Version: 2.3/2.4
OS: 
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (24.126.120.178)
Submitted by: hyc


When a slapd.conf configuration of the accesslog overlay is converted to slapd.d
format, and no logpurge interval was configured, the overlay entry in the
cn=config tree is created with a olcLogPurge attribute set to 00:00 00:00. When
slapd reads this config tree, it starts a purge task that purges everything
older than 0 seconds. The attribute should not be created at all when the
interval is zero. This has already been fixed in HEAD. overlays/accesslog.c 1.51