(ITS#3697) Seg fault because of checkpoint configuration directive

[michael@stroeder.com]

Full_Name: Michael Ströder
Version: HEAD
OS: SuSE Linux 9.3
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (83.121.33.5)


Not sure whether use of the configuaration directive 'checkpoint' is still
appropriate with back-config.

But at least slapd should not seg fault during startup when directive is present
as it does on my system.