remove incorrect call to InterceptAddrDial

[marten-seemann]

addConn is called both when we add a dialed and an accepted connection to the swarm. InterceptAddrDial is only supposed to intercept outgoing connections though. When dialing, we already call InterceptAddrDial when we compose the
list of dialable addresses:

go-libp2p-swarm/swarm_dial.go

Lines 658 to 678 in eef02f8

	func (s *Swarm) filterKnownUndialables(p peer.ID, addrs []ma.Multiaddr) []ma.Multiaddr {
	lisAddrs, _ := s.InterfaceListenAddresses()
	var ourAddrs []ma.Multiaddr
	for _, addr := range lisAddrs {
	protos := addr.Protocols()
	// we're only sure about filtering out /ip4 and /ip6 addresses, so far
	if protos[0].Code == ma.P_IP4 || protos[0].Code == ma.P_IP6 {
	ourAddrs = append(ourAddrs, addr)
	}
	}
	return addrutil.FilterAddrs(addrs,
	addrutil.SubtractFilter(ourAddrs...),
	s.canDial,
	// TODO: Consider allowing link-local addresses
	addrutil.AddrOverNonLocalIP,
	func(addr ma.Multiaddr) bool {
	return s.gater == nil || s.gater.InterceptAddrDial(p, addr)
	},
	)
	}

[raulk]

This looks fair, and intercepting outbound dials is what the contract says, so if users are using this to intercept inbounds, it's wrong usage so no need to do change management.

However, we should add an integration test here swarm <=> conngater. It makes me uneasy that this was uncaught and there are no tests here.

[prestonvanloon]

Hey guys, we have been reviewing recent updates to libp2p for prysmaticlabs/prysm#9772 and this PR seems to modify expected behavior of the ConnectionGater.

Please correct me if I am misunderstanding this change. Does this change modify the behavior such that a ConnectionGater will no longer actively reject inbound and outbound connections/dials? We are following the description in the upstream godoc here: https://github.com/libp2p/go-libp2p/blob/v0.15.1/options.go#L329-L333

[marten-seemann]

InterceptAddrDial was (incorrectly) called for incoming connections. This PR fixes that.