Encode the whois result to UTF-8

Encode the whois result to UTF-8 as htmlspecialchars() expects UTF-8 by default since PHP 5.4. If the result isn't encoded and it contains latin characters, the htmlspecialchars() output is null. Also force htmlspecialchars() to use UTF-8 for PHP<5.4 compatibility. Test case - query the domain "unihostbrasil.com.br".