Fix HttpServer documentation

sdk/lib/io/http.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.io;
 
 /**
  * HTTP status codes.
  */
 abstract class HttpStatus {
@@ skipping 150 matching lines @@
    *
    * The default value is `null`.
    */
   String serverHeader;
 
   /**
    * Default set of headers added to all response objects.
    *
    * By default the following headers are in this set:
    *
-   *    Content-Type: text/plain; charset=utf-8
-   *    X-Frame-Options: SAMEORIGIN
-   *    X-Content-Type-Options: nosniff
-   *    X-XSS-Protection: 1; mode=block
+   *     Content-Type: text/plain; charset=utf-8
+   *     X-Frame-Options: SAMEORIGIN
+   *     X-Content-Type-Options: nosniff
+   *     X-XSS-Protection: 1; mode=block
    *
    * If the `Server` header is added here and the `serverHeader` is set as
    * well then the value of `serverHeader` takes precedence.
    */
   HttpHeaders get defaultResponseHeaders;
 
   /**
    * Get or set the timeout used for idle keep-alive connections. If no further
    * request is seen within [idleTimeout] after the previous request was
    * completed, the connection is dropped.
@@ skipping 1792 matching lines @@
 class RedirectException implements HttpException {
   final String message;
   final List<RedirectInfo> redirects;
 
   const RedirectException(this.message, this.redirects);
 
   String toString() => "RedirectException: $message";
 
   Uri get uri => redirects.last.location;
 }