Optimize out what is a very expensive in-request call to
  ap_server_root_relative (and is becoming more expensive).
  Now the call happens in the config phase where it belongs.
  Note someone can hop in and transpose the stat and open
  with an open and getfileinfo if you are a performance hound.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@90563 13f79535-47bb-0310-9956-ffa450edef68