intra/tunnel: do not wipe out bridge, for now

An elusive nil ptr crashes runtime when the host process is shutting down.
although, it isn't clear just where this nil originates, the var bridge
in tunnel.go is one suspect.

Author: ignoramous

intra/tunnel.go

@@ -159,7 +159,7 @@ func (t *rtunnel) Disconnect() {
 		err0 := t.resolver.Stop()
 		err1 := t.proxies.StopProxies()
 		n := t.services.StopServers()
-		t.bridge = nil // "free" ref to the client
+		// t.bridge = nil // "free" ref to the client
 		log.I("tun: <<< disconnect >>>; err0(%v); err1(%v); svc(%d)", err0, err1, n)
 
 		t.Tunnel.Disconnect()