mod_authn_dbd, mod_authz_dbd, mod_session_dbd, mod_rewrite: Fix lifetime

of DB lookup entries independently of the selected DB engine.  PR 46421.

Suggested by: Michel Stam <michel reverze net>
Proposed by: Steven whitson <steven.whitson gmail com>
Reviewed/Extended/Committed by: ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1679181 13f79535-47bb-0310-9956-ffa450edef68