Fix missing human-readable error information in SSL log messages:

* mod_ssl.c (ssl_cleanup_pre_config): Don't free the error strings,
since they can't be loaded again once.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk/modules/ssl@101624 13f79535-47bb-0310-9956-ffa450edef68