various SSLCACertificatePath fixes:

- return value from apr_dir_read() was checking != APR_SUCCESS rather
  than == APR_SUCCESS, so no certs were ever loaded.

- wasn't checking return value of apr_dir_open(), now log an error and
  ssl_die() on failure.

- don't bother trying to load directories


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk/modules/ssl@93634 13f79535-47bb-0310-9956-ffa450edef68