title: Haproxy add response header for subdomain
body: <p>I tried to add a header for a subdomain this way:</p>
  
  <pre><code>acl ExampleRule hdr(host) -i subdomain.example.com
  http-response set-header X-test "test" if ExampleRule
  </code></pre>
  
  <p>But when I load the page it isn't added. Does anyone know how to add it?</p>