netstd Server: Add IPv6

Unlike servers in other languages (tested: cpp & python), netstd (Csharp) listens only on IPv4.
This can cause errors and delays on clients if they use "localhost" for hostname.
diff --git a/lib/netstd/Thrift/Transport/Server/TServerSocketTransport.cs b/lib/netstd/Thrift/Transport/Server/TServerSocketTransport.cs
index 3a4fed4..31ecef3 100644
--- a/lib/netstd/Thrift/Transport/Server/TServerSocketTransport.cs
+++ b/lib/netstd/Thrift/Transport/Server/TServerSocketTransport.cs
@@ -44,7 +44,8 @@
             try
             {
                 // Make server socket
-                _server = new TcpListener(IPAddress.Any, port);
+		_server = new TcpListener(IPAddress.IPv6Any, port);
+                _server.Server.SetSocketOption(SocketOptionLevel.IPv6, SocketOptionName.IPv6Only, false);
                 _server.Server.NoDelay = true;
             }
             catch (Exception)