Don't show email addresses to moderators on user list

[dfabulich]

In the dev environment, login as ifdbadmin@ifdb.org/secret and navigate to http://localhost:8080/adminops?users&sortby=new

Actual: We show all email addresses here (private and public) in a report
Expected: We should spoilerize these emails, ideally with a single button to "show all emails"

Note that we delete all email addresses from the IF Archive DB backup, so you won't see many email addresses here; most likely you'll only just see one email address: ifdbadmin@ifdb.org. But if you create new user accounts in your dev environment, they'll show up on the report.

[dfabulich]

@bg filed a pull request iftechfoundation/ifdb#104 to address this