Add missing condition on LogFile endpoint

See gh-16298

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/logging/LogFileWebEndpointAutoConfiguration.java

 /*
- * Copyright 2012-2017 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.
@@ -16,6 +16,7 @@
 
 package org.springframework.boot.actuate.autoconfigure.logging;
 
+import org.springframework.boot.actuate.autoconfigure.endpoint.condition.ConditionalOnEnabledEndpoint;
 import org.springframework.boot.actuate.logging.LogFileWebEndpoint;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.autoconfigure.condition.ConditionMessage;
@@ -38,6 +39,7 @@ import org.springframework.util.StringUtils;
  * @since 2.0.0
  */
 @Configuration
+@ConditionalOnEnabledEndpoint(endpoint = LogFileWebEndpoint.class)
 @EnableConfigurationProperties(LogFileWebEndpointProperties.class)
 public class LogFileWebEndpointAutoConfiguration {
 

spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/logging/LogFileWebEndpointAutoConfigurationTests.java

 /*
- * 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.
@@ -74,7 +74,7 @@ public class LogFileWebEndpointAutoConfigurationTests {
 				.withPropertyValues("logging.file:test.log",
 						"management.endpoint.logfile.enabled:false")
 				.run((context) -> assertThat(context)
-						.hasSingleBean(LogFileWebEndpoint.class));
+						.doesNotHaveBean(LogFileWebEndpoint.class));
 	}
 
 	@Test