Fix the ownership delegation for proxy directory under `make install'. This

now uses the same check as APACI's configure but is a install-time decision
and not a configure-time decision (which can be especially important for
package maintainers).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@83090 13f79535-47bb-0310-9956-ffa450edef68