Merge r611466 from trunk:

mod_proxy_ftp: Fix base for directory listings.
PR 27834

Submitted by: niq
Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@631360 13f79535-47bb-0310-9956-ffa450edef68