mailman-2.1.14_2 and _3, CGI wrapper Error

[n dhert]

Yesterday morning I upgraded mailman-2.1.14_1 to 2.1.14_2

Since then none of my mailings lists (that worked for years) works.
http://myserver.mysubdom.mydom/mailman/listinfo
(or any other mailman command) gives

Mailman CGI error!!!
The Mailman CGI wrapper encountered a fatal error.
This entry is being stored in your syslog:
Group mismatch error.  Mailman expected the CGI
wrapper script to be executed as group "@CGI_GROUP@", but
the system's web server executed the CGI script as
group "www".  Try tweaking the web server to run the
script as group "@CGI_GROUP@", or re-run configure,
providing the command line option `--with-cgi-gid=www'.

I know there is an entry in /usr/ports/UPDATING
20110613:
  AFFECTS: users of mail/mailman with postfix
  AUTHOR: crees at FreeBSD.org
  The mailman port has for some time specified the incorrect group when
  using with Postfix, as reported in ports/142000. The group for mailman
  is now nobody if compiled with Postfix. Be prepared to make appropriate
  adjustments if you have compensated for this bug in the past.
But I don't use postfix, I Use sendmail

I saw there today mailman-2.1.14_3, so I portupgraded to that version and
also did
# /usr/local/mailman/bin/mailmanctl stop
# /usr/local/mailman/bin/mailmanctl start

but this doesn't help.

Is there an error in de newest version?

Do I need to "Try tweaking the web server to run the
script as group "@CGI_GROUP@", or re-run configure,
providing the command line option `--with-cgi-gid=www'."
How should this be done? is this a change in Apache web server ?
and how exactly??