update branch to main (#160)

Author: v1v

Jenkinsfile

@@ -30,7 +30,6 @@ pipeline {
   }
   parameters {
     string(name: 'MAVEN_CONFIG', defaultValue: '-B -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn', description: 'Additional maven options.')
-    booleanParam(name: 'Run_As_Master_Branch', defaultValue: false, description: 'Allow to run any steps on a PR, some steps normally only run on master branch.')
     booleanParam(name: 'test_ci', defaultValue: true, description: 'Enable test')
     booleanParam(name: 'doc_ci', defaultValue: true, description: 'Enable doc validation')
   }

README.md

@@ -1,4 +1,4 @@
-[![Build Status](https://apm-ci.elastic.co/buildStatus/icon?job=apm-agent-java%2Fecs-logging-java-mbp%2Fmaster)](https://apm-ci.elastic.co/job/apm-agent-java/job/ecs-logging-java-mbp/job/master/)
+[![Build Status](https://apm-ci.elastic.co/buildStatus/icon?job=apm-agent-java%2Fecs-logging-java-mbp%2Fmain)](https://apm-ci.elastic.co/job/apm-agent-java/job/ecs-logging-java-mbp/job/main/)
 [![Maven Central](https://img.shields.io/maven-central/v/co.elastic.logging/ecs-logging-java-parent.svg)](https://search.maven.org/search?q=g:co.elastic.logging)
 
 # ECS-based logging for Java applications