Specification of the user parameter is ineffective to unix socket.

[ryuu]

The owner of '/var/run/milter-greylist/greylist.sock' continues being 'root.root' even if it describes as follows:
----
$ cat /etc/default/milter-greylist
ENABLED=1
PIDFILE="/var/run/milter-greylist.pid"
SOCKET="/var/run/milter-greylist/greylist.sock"
USER="greylist"
----

For check, run as follow:
----
$ sudo /usr/sbin/milter-greylist -u greylist -p /var/run/milter-greylist/greylist.soc
----
Result, the owner of '/var/run/milter-greylist/greylist.sock' continues being 'root.root'.

ubuntu: 12.04 Precise Pangolin
milter-greylist: 4.3.9-1