Don't emit suppressed email addresses

[theory]

CPAN authors can opt out of receiving email sent to [email protected]. For those users, the cpan.org email address should not be shown or linkable in the API or on the site. For example, author ILLY has opted out. On his search.cpan.org page, his email address is listed as "CENSORED". On his metaCPAN page, however, it's a mailto: link. It should not be, as email sent to that address will bounce (as I discovered last week).