peers.sh result can be incorrect

[bboreham]

Observed in the log files of weave in a three-node cluster:

INFO: 2017/10/23 08:42:23.313585 Our name is a2:ef:b2:fc:2e:ba(ip-172-31-0-233)
INFO: 2017/10/23 08:42:23.313613 Launch detected - using supplied peer list: [172.31.1.40 172.31.0.244]

INFO: 2017/10/23 08:44:24.386396 Our name is a2:cc:25:9a:cf:ca(ip-172-31-1-146)
INFO: 2017/10/23 08:44:24.386422 Launch detected - using supplied peer list: [172.31.0.233 172.31.0.244]

INFO: 2017/10/23 08:46:21.875554 Our name is 9a:d9:06:ed:a6:0a(ip-172-31-0-178)
INFO: 2017/10/23 08:46:21.875591 Launch detected - using supplied peer list: [172.31.0.233 172.31.1.146]

the IP addresses 172.31.1.40 and 172.31.0.244 are not part of the cluster.

See also #134 where the peers result is also wrong, but in that case blank.