mod_proxy_express: Fix possible use of DB handle after close.

PR 59230.

Submitted by: Petr <pgajdos suse.cz>
Reviewed/Committed by: ylavic


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1737014 13f79535-47bb-0310-9956-ffa450edef68