fix: pass subscriptions immediately on new peer connection

[gavinmcdermott]

This fix ensures that a node's current subscriptions are immediately passed to a new peer when a connection is established.

[gavinmcdermott]

Question @diasdavid: I was trying to figure a good way to test this...but the stream I imagine tapping is added as the peer connection is created. Is there an object or property somewhere, or a way to tap into the stream that I just don't know, that I could use to listen for that immediate write over the new stream?

The reason for this fix is referenced here.

[daviddias]

Thank you @gavinmcdermott 🌟

A way to test this is:

• Create 2 peers
• Subscribe to a topic in one
• Connect the two
• Check if the other one has received the subscription by checking its peerSet

What do you think?

[gavinmcdermott]

I did this last night, and it felt a little loose for some reason. I was thinking that the best test would be to listen directly on the stream and catch that message. But the black-box version works great. Update on the way....