Remove the explicit setting of the hostname in the response

lib/src/server/server.dart

 // Copyright (c) 2014, 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.
 
 library application;
 
 import 'dart:async';
 import 'dart:convert' show UTF8;
 import 'dart:io';
 
 import 'context_registry.dart';
 import 'http_wrapper.dart';
 
 void _info(String message) {
   var formattedMessage = "${new DateTime.now()}: " + message;
   print(formattedMessage);
 }
 
-String _getHostname() =>
-    (Process.runSync('/bin/hostname', []).stdout as String).trim();
-
 class AppEngineHttpServer {
   final ContextRegistry _contextRegistry;
 
   final String _hostname;
   final int _port;
 
-  final String _localHostname;
   final Completer _shutdownCompleter = new Completer();
   int _pendingRequests = 0;
 
   HttpServer _httpServer;
 
   AppEngineHttpServer(this._contextRegistry,
                       {String hostname: '0.0.0.0', int port: 8080})
-      : _localHostname = _getHostname(), _hostname = hostname, _port = port;
+      : _hostname = hostname, _port = port;
 
   Future get done => _shutdownCompleter.future;
 
   void run(applicationHandler(request, context)) {
     var serviceHandlers = {
         '/_ah/start' : _start,
         '/_ah/health' : _health,
         '/_ah/stop' : _stop
     };
 
     HttpServer.bind(_hostname, _port).then((HttpServer server) {
       _httpServer = server;
 
       server.listen((HttpRequest request) {
         var appengineRequest = new AppengineHttpRequest(request);
 
         _info("Got request: ${appengineRequest.uri}");
 
-        // Default handling is sending the request to the aplication.
+        // Default handling is sending the request to the application.
         var handler = applicationHandler;
 
         // Check if the request path is one of the service handlers.
         String path = appengineRequest.uri.path;
         for (var pattern in serviceHandlers.keys) {
           if (path.startsWith(pattern)) {
             handler = serviceHandlers[pattern];
             break;
           }
         }
 
         _pendingRequests++;
         var context = _contextRegistry.add(appengineRequest);
-        /*
-         * This sets the 'Server' header in the http response to the hostname
-         * of the machine the application is running on.
-         * It seems like the AppEngine VmRuntime stub (on the other end) will
-         * not accept the response if we use the default value.
-         */
-        appengineRequest.response.headers.set('Server', _localHostname);
         appengineRequest.response.registerHook(
             () => _contextRegistry.remove(appengineRequest));
 
         appengineRequest.response.done.catchError((error) {
           _info("Error while handling response: $error");
           _pendingRequests--;
           _checkShutdown();
         });
 
         handler(appengineRequest, context);
@@ skipping 37 matching lines @@
     response.headers.contentType =
         new ContentType('text', 'plain', charset: 'utf-8');
     response.headers.set("Cache-Control", "no-cache");
     response.headers.set("Server", _hostname);
     response.contentLength = data.length;
     response.statusCode = statusCode;
     response.add(data);
     response.close();
   }
 }