Added more info to message

Jenkinsfile

@@ -23,7 +23,7 @@ node('local') {
             }
 
             stage('Check git on changes') {
-                sh 'if [ $(git diff | wc -l) -eq 0 ]; then true; else echo "[ERROR] Git is not clean anymore after build"; false; fi'
+                sh 'if [ $(git diff | wc -l) -eq 0 ]; then true; else echo "[ERROR] Git is not clean anymore after build"; git diff; echo "[ERROR] This might be caused by reformated code, if so run maven locally"; false; fi'
             }
 
             stage('Check Documentation') {