[ic] Interchange demo: userdb mail_list field cannot be set to empty

[Jon Jensen]

FYI, I released 5.7.3 with Ton's commit intact, figuring it isn't a big 
enough problem to hold up a developer release. As Peter Ajamian noted on 
IRC, it would only affect a new Standard demo install anyway, not an 
upgrade.

I presume those who discussed this will come up with a good solution and 
commit it soon before 5.7.4 comes out. Right? :)

Thanks,
Jon

-- 
Jon Jensen
End Point Corporation
http://www.endpoint.com/