(ITS#6906) fix Admin guide cachesize calculations to remove refence to Hash-format

[Tim.Mooney@ndsu.edu]

Full_Name: Tim Mooney
Version: 2.4.25
OS: Linux, Solaris
URL: ftp://ftp.openldap.org/incoming/TimMooney-110412-04.patch
Submission from: (NULL) (2001:4930:106:0:18bb:1140:fa3d:f713)


As I mentioned here:

   http://www.openldap.org/lists/openldap-technical/201104/msg00088.html

and Quanah clarified here:

   http://www.openldap.org/lists/openldap-technical/201104/msg00123.html

The admin guide chapter on tuning still mentions that indexes are in Hash
format,
though that's no longer true.

I've uploaded patch TimMooney-110412-04.patch against HEAD that clarifies that
indexes are now also in B-tree format and so the same calculations for cache on
dn2id can be used with each index.

I also corrected one other typo, changing

            To avoid thrashing the, your cache

to

            To avoid thrashing, your cache