GitLab

The context-cancelled watchdog goroutine may start running way after the
handshake has finished and the associated context has been cancelled (by the
executeDial() function in go-libp2p-swarm usuaully).

This results in the connection being closed right after being stablished.

TLS 1.3 support was recently made opt-in in Go 1.12, so we need to
explicitly enable it.

TLS 1.3 will require Go >= 1.12, so we don't need any fixes that were
specific to Go 1.10 any more.