Use apr_temp_dir_get for htpasswd

Submitted by: Guenter Knauf <eflash gmx.net>
Reviewed by: thommay, bnicholes, jjclar


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@103208 13f79535-47bb-0310-9956-ffa450edef68