fix #147 by adding support for skipping STUN

[lithp]

No description provided.

[lithp]

I'm not sure which PR should make it in, this one is smaller than #155 but usage is less intuitive, adding it as an alternative but no worries if you prefer #155!

[ogenev]

My personal preference is #155 😇 because It is also fixing the issue for the target node and I think adding a flag оn whether we want to use a STUN server or not solves the problem on a more fundamental level.

[njgheorghita]

I'm about 50/50 between these two solutions. I'd agree #155 is more comprehensive. But, it's hard for me to gauge whether or not that much comprehension will be useful or unnecessary bloat down the road? But, it seems to me that for whatever reason, we might at some point want the ability to skip stunned external ip's (maybe when dealing with testnets - especially if we end up on k8s at some point?) so I'm leaning towards #155

[njgheorghita]

@lithp Any final thoughts/objections? Otherwise let's move ahead with #155

[lithp]

I'm happy with #155 , let's merge that one!