Prepare 2.4.x branch

Author: snicoll

buildSrc/src/main/java/org/springframework/boot/build/AsciidoctorConventions.java

@@ -166,7 +166,7 @@ private void configureCommonAttributes(Project project, AbstractAsciidoctorTask
 
 	private String determineGitHubTag(Project project) {
 		String version = "v" + project.getVersion();
-		return (version.endsWith("-SNAPSHOT")) ? "master" : version;
+		return (version.endsWith("-SNAPSHOT")) ? "2.4.x" : version;
 	}
 
 	/**

ci/parameters.yml

@@ -5,7 +5,7 @@ github-repo: "https://github.com/spring-projects/spring-boot.git"
 github-repo-name: "spring-projects/spring-boot"
 docker-hub-organization: "springci"
 artifactory-server: "https://repo.spring.io"
-branch: "master"
+branch: "2.4.x"
 milestone: "2.4.x"
 build-name: "spring-boot"
 concourse-url: "https://ci.spring.io"

spring-boot-project/spring-boot-docs/src/docs/asciidoc/attributes.adoc

@@ -12,8 +12,8 @@
 :docinfo: shared,private
 
 :spring-boot-artifactory-repo: snapshot
-:github-tag: master
-:spring-boot-version: current
+:github-tag: 2.4.x
+:spring-boot-version: 2.4.x
 
 :github-repo: spring-projects/spring-boot
 :github-raw: https://raw.githubusercontent.com/{github-repo}/{github-tag}