How do I force portupgrade to fetch distfiles using active ftp?

[Peter Olsson]

Recently portupgrade in our servers has started failing some
upgrades because it can't fetch the distfiles. This is due to
policy not allowing passive ftp. But when I try manual ftp or
manual fetch to get these distfiles, active ftp is used by default
and the fetches work fine. I have these in shell environment:
FTPMODE=active
FTP_PASSIVE_MODE=NO

We see this problem in FreeBSD versions 4, 5 and 6.
Latest version of portupgrade at all times.

How do I make portupgrade always use active ftp?

Thanks!

-- 
Peter Olsson                    pol at leissner.se