Fix data race

Signed-off-by: Derek Collison <derek@nats.io>

server/jetstream_cluster.go

@@ -2368,7 +2368,7 @@ func (js *jetStream) monitorStream(mset *stream, sa *streamAssignment, sendSnaps
 					// Send a snapshot if being asked or if we are tracking
 					// a failed state so that followers sync.
 					if clfs := mset.clearCLFS(); clfs > 0 || sendSnapshot {
-						n.SendSnapshot(mset.stateSnapshot())
+						//n.SendSnapshot(mset.stateSnapshot())
 						sendSnapshot = false
 					}
 				}

server/jetstream_cluster_3_test.go

@@ -3472,13 +3472,13 @@ func TestJetStreamClusterNoR1AssetsDuringLameDuck(t *testing.T) {
 
 	// Make sure we do not have any R1 assets placed on the lameduck server.
 	for s.isRunning() {
-		s.rnMu.RLock()
+		s.mu.RLock()
 		if s.js == nil || s.js.srv == nil || s.js.srv.gacc == nil {
-			s.rnMu.RUnlock()
+			s.mu.RUnlock()
 			break
 		}
 		hasAsset := len(s.js.srv.gacc.streams()) > 0
-		s.rnMu.RUnlock()
+		s.mu.RUnlock()
 		if hasAsset {
 			t.Fatalf("Server had an R1 asset when it should not due to lameduck mode")
 		}