Polish "Allow Tomcat be destroyed regardless of exceptions"

See gh-16892

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/web/embedded/tomcat/TomcatWebServer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 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.

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/web/embedded/tomcat/TomcatServletWebServerFactoryTests.java

@@ -526,6 +526,7 @@ public class TomcatServletWebServerFactoryTests
 	@Test
 	public void exceptionThrownOnContextListenerDestroysServer() {
 		TomcatServletWebServerFactory factory = new TomcatServletWebServerFactory(0) {
+
 			@Override
 			protected TomcatWebServer getTomcatWebServer(Tomcat tomcat) {
 				try {
@@ -536,6 +537,7 @@ public class TomcatServletWebServerFactoryTests
 							.isEqualTo(LifecycleState.DESTROYED);
 				}
 			}
+
 		};
 		assertThatExceptionOfType(WebServerException.class)
 				.isThrownBy(() -> factory.getWebServer((context) -> context