Merge branch 'JenkinsOwnerDefault' into 'master'

JENKINS_OWNER default no longer needed

See merge request exedio/cope!1258

Jenkinsfile

@@ -184,10 +184,7 @@ try
 
 	parallelBranches["Network"] = {
 		nodeCheckoutAndDelete {
-			def mainImage = docker.build(
-				imageName('Network'),
-				'--build-arg JDK=' + jdk + ' ' +
-				'conf/main')
+			def mainImage = mainImage(imageName("Network"))
 			mainImage.inside(
 				"--cap-drop all " +
 				"--security-opt no-new-privileges " +

conf/main/Dockerfile

@@ -9,8 +9,7 @@ apt-get install --no-install-recommends --assume-yes \
 rm -rf /var/lib/apt/lists/*
 EOF
 
-# TODO drop default once there is no JenkinsfileXxx anymore
-ARG JENKINS_OWNER=1001:1001
+ARG JENKINS_OWNER
 RUN <<EOF
 set -e
 mkdir /var/jenkins-build-survivor