Fix issue with chunked keep-alive responses when the initial chunk content
starts with a NULL byte.

* flood_socket_keepalive.c
  (keepalive_read_chunk): Don't inspect resp->chunk with respect to
  validity; re-order comparisons to make a bit more sense.
  (keepalive_recv_resp): Be sure that chunk_length is always initialized.


git-svn-id: https://svn.apache.org/repos/asf/httpd/flood/trunk@699195 13f79535-47bb-0310-9956-ffa450edef68