check for monitor server start error

Author: andyxning

server/server.go

@@ -1471,7 +1471,9 @@ func (s *Server) startMonitoring(secure bool) error {
 	s.mu.Unlock()
 
 	go func() {
-		srv.Serve(httpListener)
+		if err := srv.Serve(httpListener); err != nil {
+			s.Fatalf("Error starting monitor on %q: %v", hp, err)
+		}
 		srv.Handler = nil
 		s.mu.Lock()
 		s.httpHandler = nil

server/server_test.go

@@ -1162,6 +1162,8 @@ func TestConnectErrorReports(t *testing.T) {
 
 	remoteURLs := RoutesFromStr("nats://127.0.0.1:1234")
 
+	s.Shutdown()
+
 	opts = DefaultOptions()
 	opts.ConnectErrorReports = 3
 	opts.Cluster.Port = -1