use local port in gfwlist updater

shadowsocks-csharp/Controller/GfwListUpdater.cs

@@ -6,6 +6,7 @@ using System.IO;
 using Shadowsocks.Properties;
 using SimpleJson;
 using Shadowsocks.Util;
+using Shadowsocks.Model;
 
 namespace Shadowsocks.Controller
 {
@@ -42,10 +43,10 @@ namespace Shadowsocks.Controller
             }
         }
 
-        public void UpdatePACFromGFWList()
+        public void UpdatePACFromGFWList(Configuration config)
         {
             WebClient http = new WebClient();
-            http.Proxy = new WebProxy(IPAddress.Loopback.ToString(), 8123);
+            http.Proxy = new WebProxy(IPAddress.Loopback.ToString(), config.localPort);
             http.DownloadStringCompleted += http_DownloadStringCompleted;
             http.DownloadStringAsync(new Uri(GFWLIST_URL));
         }

shadowsocks-csharp/Controller/ShadowsocksController.cs

@@ -178,7 +178,7 @@ namespace Shadowsocks.Controller
         {
             if (gfwListUpdater != null)
             {
-                gfwListUpdater.UpdatePACFromGFWList();
+                gfwListUpdater.UpdatePACFromGFWList(_config);
             }
         }