Escape IPv6 address regardless of whether port is specified.

Author: Don McCurdy

lib/XMLHttpRequest.js

@@ -343,10 +343,11 @@ exports.XMLHttpRequest = function() {
 
     // Set the Host header or the server may reject the request
     headers.Host = host;
+    // IPv6 addresses must be escaped with brackets
+    if (url.host[0] === "[") {
+      headers.Host = "[" + headers.Host + "]";
+    }
     if (!((ssl && port === 443) || port === 80)) {
-      if (url.host[0] === '[') {
-        headers.Host = '[' + headers.Host + ']';
-      }
       headers.Host += ":" + url.port;
     }