fix for changelist posting to mattermost

Jenkinsfile

@@ -1,6 +1,8 @@
 #!/usr/bin/env groovy
 
 node('master') {
+    checkout scm
+    
     def changelog = getChangeLog currentBuild
 
     mattermostSend "Building ${env.JOB_NAME} #${env.BUILD_NUMBER} \n Change Log: \n ${changelog}"