Disable network join in Hazelcast samples

samples/hazelcast-spring/src/main/java/sample/SessionConfig.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2016 the original author or authors.
+ * Copyright 2014-2018 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,7 +42,8 @@ public class SessionConfig {
 		int port = SocketUtils.findAvailableTcpPort();
 
 		config.getNetworkConfig()
-				.setPort(port);
+				.setPort(port)
+				.getJoin().getMulticastConfig().setEnabled(false);
 
 		System.out.println("Hazelcast port #: " + port);