Update Jenkinsfile

Jenkinsfile

@@ -3,7 +3,7 @@ pipeline {
     stages {
         stage('Build') {
             steps {
-                sh 'echo $COMMIT_ID'
+                sh '$(echo ${GIT_COMMIT} | cut -c 1-8)'
                 //sh '/var/jenkins_home/plugins/apache-maven-3.6.3/bin/mvn clean package'
             }
         }