Fix the byterange filter for the case where the bucket can't be

copied natively.  This will only ever happen if a bucket can be split
but not copied, because we read the bucket in apr_brigade_partition if
we can't split it.  Regardless, this is much safer.  This should also fix
all of the problems with the byterange filter.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87793 13f79535-47bb-0310-9956-ffa450edef68