Merge r1629508 from trunk:

mod_cache_socache: Change average object size
hint from 32 bytes to 2048 bytes.

Submitted by: rjung
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1634528 13f79535-47bb-0310-9956-ffa450edef68