A better fix for the mass virtual hosting security problem spotted by Lars.

This solves the problem for mod_rewrite setups as well as mod_vhost_alias.
Submitted by:	Ben Hyde
Reviewed by:	Tony Finch


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@84339 13f79535-47bb-0310-9956-ffa450edef68