tun2: no connections means no connections

lib/tun2/server.go

@@ -365,7 +365,7 @@ func (s *Server) RoundTrip(req *http.Request) (*http.Response, error) {
 	val, ok := s.domains.Get(req.Host)
 	if ok {
 		conns, ok = val.([]*Connection)
-		if !ok {
+		if !ok || len(conns) == 0 {
 			ln.Error(errors.New("no backend connected"), ln.F{
 				"action": "no_backend_connected",
 				"remote": req.RemoteAddr,