Point to mailman3 directly from the nonwg lists page

[rjsparks]

Right now, the nonwg lists page links to mailman2 endpoints, and redirects don't do the right thing with mixed-case names.

Point to mailman3 directly, and lowercase the names in the link.

See

datatracker/ietf/mailinglists/models.py

Line 22 in 39d471d

return settings.MAILING_LIST_INFO_URL % {'list_addr': self.name }