SCREEGO_STUN_EXTERNAL_IP

[dongdigua]

In some network setup (e.g. AP isolation with NAT loopback), it's good to use an external STUN server (for peers in the same AP, use the external IP as endpoint and loop back to LAN)

[jmattheis]

Thanks for the feature request. I'm not sure many users need this, so I'd like to wait for more feedback until accepting contributions for this.