Ticket 48831 - Autotune dncache with entry cache.
Bug Description: Previously we only tuned db and entry cache. We
needed to tune the dncache to prevent over-access to id2entry.
Fix Description: Tune the dncache as 10% of the entrycache value
and entrycache now gets 90% of the allocation previously.
https://pagure.io/389-ds-base/issue/48831
Author: wibrown
Review by: mreynolds (Thanks!)