Fix JMS health indicator

This commit improves the JMS health indicator to identify a broken broker
that uses failover. An attempt to start the connection is a good way to
make sure that it is effectively available.

Closes gh-6818

spring-boot-actuator/src/main/java/org/springframework/boot/actuate/health/JmsHealthIndicator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2015 the original author or authors.
+ * Copyright 2012-2016 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.
@@ -37,6 +37,7 @@ public class JmsHealthIndicator extends AbstractHealthIndicator {
 	protected void doHealthCheck(Health.Builder builder) throws Exception {
 		Connection connection = this.connectionFactory.createConnection();
 		try {
+			connection.start();
 			builder.up().withDetail("provider",
 					connection.getMetaData().getJMSProviderName());
 		}