Don't respect the Server header field as set by modules and CGIs.

As with 1.3, for proxy requests any such field is from the origin
server; otherwise it will have our server info as controlled by
the ServerTokens directive.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@100182 13f79535-47bb-0310-9956-ffa450edef68