resolve some segfaults see when doing such restarts.
(Justin tweaked the palloc/memset in favor of calloc.)
Submitted by: Aaron Bannert
Reviewed by: Greg Ames, Sander Striker, Justin Erenkrantz
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@94886 13f79535-47bb-0310-9956-ffa450edef68