Make sure InetUtils.executorService shuts down.

See https://github.com/spring-cloud/spring-cloud-netflix/issues/491

spring-cloud-commons/src/main/java/org/springframework/cloud/util/UtilAutoConfiguration.java

@@ -21,7 +21,7 @@ public class UtilAutoConfiguration {
 		return new InetUtilsProperties();
 	}
 
-	@Bean
+	@Bean(destroyMethod = "close")
 	@ConditionalOnMissingBean
 	public InetUtils inetUtils(InetUtilsProperties properties) {
 		return new InetUtils(properties);