Changing host_name domain does not update virtual-mailman

[Cedders-users]

We're running Mailman 2.1.5-8sarge5 and Postfix 2.1.5-9.

Making a change to the "Host name this list prefers for email" on the
"General Options" web page does not create or update a virtual_host entry
if needed in the data/virtual-mailman file. Hence this can cause
unexpected bounces to addresses associated with that list.

The workaround we use for this is to run genaliases regularly.

[http://sourceforge.net/tracker/index.php?func=detail&aid=1809697&group_id=103&atid=100103]