Restore the apr_pool_clear calls to main.c in case we have

third-parties who are overriding the open_logs hook, in which case
they'd miss the plog being cleared.

Submitted by:	Justin <jerenkrantz@apache.org>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@92771 13f79535-47bb-0310-9956-ffa450edef68