vulcand error reported: failed to add middleware: Max connections should be >= 0

[glycerine]

Copying all the etdctl setup statements from the manual (http://www.vulcanproxy.com/proxy.html#etcd), then starting vulcand, I get the following error. Vulcand still runs (no panic), but perhaps a max connections setting needs to be added to the example in the manual?

$ etcdctl set /vulcand/hosts/localhost/locations/loc1/middlewares/ratelimit/rl1 '{"Type": "ratelimit", "Middleware":{"Requests":1, "PeriodSeconds":1, "Burst":3, "Variable": "client.ip"}}'
{"Type": "ratelimit", "Middleware":{"Requests":1, "PeriodSeconds":1, "Burst":3, "Variable": "client.ip"}}
$ etcdctl set /vulcand/hosts/localhost/locations/loc1/middlewares/connlimit/rl1 '{"Type": "connlimit", "Middleware":{"Requests":1, "PeriodSeconds":1, "Burst":3, "Variable": "client.ip"}}'
{"Type": "connlimit", "Middleware":{"Requests":1, "PeriodSeconds":1, "Burst":3, "Variable": "client.ip"}}
$ vulcand
ERROR Oct  4 21:26:22.217: PID:4504 [mux.go:451] failed to add middleware: Max connections should be >= 0