[sslh] Creating a new filter for SoftEther VPN

[Cerem Cem ASLAN]

> If it's Ethernet over HTTPS, you should be able to probe it
> as TLS and route it to the appropriate server using
> sni_hostname.

Thanks. I just searched net and I found a clue that it might be
possible to use Nginx as a proxy for SE:
https://b.d3v.ma3x.org/nginx-ssl-reverse-proxy-sni-softether/ (it
seems Russian but I think Google Translate would help me
understanding)