haproxy not configured right on single node with couchdb+soledad+webapp service

root@single1:~# tail /etc/haproxy/haproxy.cfg 
  option   allbackups           # balance among all backups, not just one.

  bind localhost:4096

  default-server inter 3000 fastinter 1000 downinter 1000 rise 2 fall 1

  # single1
  server couchdb_0 localhost:0  weight 10 check

so the port is not set correctly in the last line

(from redmine: created on 2013-09-12, closed on 2013-10-03, relates #3599 (closed))