Fix some broken documentation links

Author: Phillip Webb

spring-boot-docs/src/main/asciidoc/cloud-deployment.adoc

@@ -127,8 +127,8 @@ access application information (such as the public URL of the application) and s
 information (such as database credentials). See `VcapApplicationListener` Javdoc for
 complete details.
 
-TIP: The http://spring.io/projects/spring-cloud[Spring Cloud] project is a better fit
-for tasks such as configuring a DataSource; and you can also use Spring Cloud with
+TIP: The https://github.com/spring-projects/spring-cloud[Spring Cloud] project is a better
+fit for tasks such as configuring a DataSource; and you can also use Spring Cloud with
 Heroku too!
 
 

spring-boot-docs/src/main/asciidoc/howto.adoc

@@ -746,7 +746,7 @@ If Groovy is on the classpath you should be able to configure Logback with
 
 [[howto-configure-log4j-for-logging]]
 === Configure Log4j for logging
-Spring Boot supports http://logging.apache.org/log4j/1.x/[Log4j] for logging
+Spring Boot supports http://logging.apache.org/log4j[Log4j] for logging
 configuration, but it has to be on the classpath. If you are using the starter poms for
 assembling dependencies that means you have to exclude logback and then include log4j
 back. If you aren't using the starter poms then you need to provide `commons-logging`

spring-boot-docs/src/main/asciidoc/production-ready-features.adoc

@@ -163,7 +163,7 @@ To provide custom health information you can register a Spring bean that impleme
 ----
 
 Spring Boot also provides a
-{sc-spring-boot-actuator}/health/SimpleHealthIndicator/{sc-ext}[`SimpleHealthIndicator`]
+{sc-spring-boot-actuator}/health/SimpleHealthIndicator.{sc-ext}[`SimpleHealthIndicator`]
 implementation that attempts a simple database test.