RewriteEngine on
RewriteCond %{HTTPS} off
RewriteCond %{HTTP:X-Forwarded-SSL} !on
RewriteCond %{HTTP_HOST} ^zsl\.hr$ [OR]
RewriteCond %{HTTP_HOST} ^www\.zsl\.hr$
RewriteRule ^/?$ "https\:\/\/zsl\.hr\/" [R=301,L]