fix: deny connections to peers in the right place (#1627)
fix: deny connections to peers in the right place (#1627)

The previous location would prevent explicit calls to `Connect`, but not
implicit connections on `NewStream`. Given that the host calls `Connect`
before calling `NewStream`, it's unclear whether or not this would
likely be triggered by user code, but we still need to fix it.
libp2p/go-libp2p,libp2p/go-libp2p