Encode hostname parameter contents in javascript for diag_dns.php. Fixes #7999
(cherry picked from commit 43746e1b4ef6fec0e9c915495aa3926a6b97e7a3)
Encode hostname parameter contents in javascript for diag_dns.php. Fixes #7999
(cherry picked from commit 43746e1b4ef6fec0e9c915495aa3926a6b97e7a3)