regression in db_replicator's behavior when bind_ip is set to a non-canonical (ring-style) short form IPv6 address

in container-server.conf and account-server.conf, we have used bind_ip in the form:

bind_ip = 2001:0db8:0000:8007:0000:0000:0011:0001

The old code (at least in 2.2.0) that enumerated local IPs ignored bind_ip entirely and compared the ring contents with the local IPs of the server. The new 2.4.0 code uses what's given in bind_ip as a local IP without sanitizing or shortening it, which leads to a mismatch and the container/account replicators will ignore their local mounts as the strings are not equal to the ring contents.

in whataremyips() inside swift.common.utils, we could return [sockaddr[0]] instead of [bind_ip], but I don't know if this is the best way of canonicalizing the IPv6.