Nodes sometimes fail to connect

[tomaka]

Reproduction steps:

• Open two terminals.
• Run the chat example in both. There is chance that you get a "Connection reset by peer" error in one of them.
• If you don't get the error, kill one of the chats and restart it until you get the error.

[2019-01-22T15:20:02Z ERROR libp2p_yamux] connection error: decode error: i/o error: I/O error: Connection reset by peer (os error 104)

I initially thought that it was an error about closing the previous connection (from before we restart the chat), but this can happen on first try even when both chat examples were closed.

This can also possibly be caused by the dialing priority system not working properly.

[tomaka]

This may be the underlying cause of paritytech/substrate#1335

[tomaka]

No longer happens. Probably got fixed at the same time as the simultaneous dialing.