If a higher-level filter handles the the byterange aspects of a

If a higher-level filter handles the the byterange aspects of a
request, then the byterange filter should not try to redo the
work.  The most common case of this happening, is a byterange
request going through the proxy, and the origin server handles
the byterange request.  The proxy should ignore it.

Submitted by:	Graham Leggett <minfrin@sharp.fm>

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@88873 13f79535-47bb-0310-9956-ffa450edef68