- Fix segfault in core_output_filter when we are passed an empty brigade.

- Fix segfault in core_output_filter when we are passed an empty brigade.
- Stash the remainder of the brigade in more when we see a flush bucket.
  Previous to this commit, we would only process the buckets before the
  flush on a HTTP/1.0 request and then return.

We are proably only finding this now since we now correctly check for
keepalive connection status.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@95896 13f79535-47bb-0310-9956-ffa450edef68