Duplicate changelogs in jenkins pipeline script

I am working on how to use the new Jenkins Pipeline Plugin with the Jenkinsfile in the scm of the project (we use GIT).

The job script is loaded from the SCM ('Pipeline script from SCM' option) and in the Jenkinsfile script I do a checkout scm.

The problem is that the commits are duplicated. In the build directory, there is 2 changelog.xml with the same commits and so the changes view can be very messy :

Summary

1. FNC71010 - Ajout des traductions au launcher (details)
Commit 5a676ee1448b72f1b99227e8832b01081aa1bc6d by thierry
The file was modified   Deploy_serveur/resources/config/trad.properties

Summary

1.FNC71010 - Ajout des traductions au launcher (details)
Commit 5a676ee1448b72f1b99227e8832b01081aa1bc6d by thierry
The file was modified   Deploy_serveur/resources/config/trad.properties

The problem occurs also with in the multibranch pipeline.

Here is the Jenkinsfile content :

#!groovy

node {
    stage 'initialisation'
    def repertoire = "directory"

    def pipeline
    dir(repertoire) {
        checkout scm
        pipeline = load 'pipeline.groovy'
    }
    pipeline.initialisation(repertoire)
    pipeline.build()
    pipeline.runTestsRapides()
    pipeline.copieResultats()
}

Am I doing something wrong ?

Jenkins version : 1.642.2 (docker) Pipeline version : 1.15 Git plugin : 2.4.3