[Fix] Move it out

As a preventive move. See: issue #235

websocket-sharp/Net/HttpListener.cs

@@ -433,19 +433,21 @@ namespace WebSocketSharp.Net
 
     private void cleanupContextRegistry ()
     {
+      HttpListenerContext[] ctxs = null;
       lock (_ctxRegistrySync) {
         if (_ctxRegistry.Count == 0)
           return;
 
         // Need to copy this since closing will call the UnregisterContext method.
         var keys = _ctxRegistry.Keys;
-        var ctxs = new HttpListenerContext[keys.Count];
+        ctxs = new HttpListenerContext[keys.Count];
         keys.CopyTo (ctxs, 0);
         _ctxRegistry.Clear ();
+      }
+
       for (var i = ctxs.Length - 1; i >= 0; i--)
         ctxs[i].Connection.Close (true);
     }
-    }
 
     private void cleanupWaitQueue ()
     {