hostile.set allows for hostname='' (empty string)

[Emil Marklund]

Perhaps it would be neat to perform some simple hostname validation too, see https://stackoverflow.com/questions/106179/regular-expression-to-match-dns-hostname-or-ip-address

[Feross Aboukhadijeh]

Thanks for reporting this issue. Due to time constraints, I don't have any plans to work on this so I'm going to close it. If you would like to see it fixed, please send a pull request!