New contacts field in registrant struct

[DarkMristov]

Some whois responses contain admin contact urls. Maybe we should parse them too.

See example by querying:

# Pay attention to field "admin-contact"
$ whois salenames.ru

At the moment we've encountered such field only in one domain. If more domains return such field, we should add a new field to regex structures.

Domains with contact admin field:

• salenames.ru