Unison on 4.3 - tcp6 only

[Steven Surdock]

Greetings, it seems that unison-2.27.57 only binds to tcp6 when run with
the '-socket xxx' option.  I have been able to work around this using
the '-host xx.xx.xx.xx' option, which then binds to the IPv4 address
specified.

-Steve S.