Work around the behaviour change in latest Spring 4.2 snapshots

The changes made in spring-projects/spring-framework@e403aefe cause
SampleTomcatTwoConnectorsApplication to fail to launch. The port bean,
typed as an int, is coerced into an Integer when the bean’s created. The
port() method is then called, and the proxy’s bean method interceptor
complains as it’s expecting the port bean to be an int but it’s actually
an Integer. Changing the port() bean method’s return type to Integer
works around the problem.

spring-boot-samples/spring-boot-sample-tomcat-multi-connectors/src/main/java/sample/tomcat/SampleTomcatTwoConnectorsApplication.java

@@ -40,7 +40,7 @@
 public class SampleTomcatTwoConnectorsApplication {
 
 	@Bean
-	public int port() {
+	public Integer port() {
 		return SocketUtils.findAvailableTcpPort();
 	}