Used Jenkins version: 2.19.1, but I'm pretty sure this behavior is also present in older jenkins versions

Steps to reproduce:

• Download the jenkins.war file
• Make sure you have an empty/not existing ~/.jenkins (or whatever JENKINS_HOME directory is used)
• From the directory where you downloaded the .war file, run `java -Djenkins.install.runSetupWizard=false -jar jenkins.war`
• When Jenkins is started, go to Manage Jenkins -> Configure System and click the "Advanced" button underneath the home directory setting at the top of the page
• Observation: the workspace root directory is specified as`${JENKINS_HOME}/workspace/${ITEM_FULLNAME}`, as it is documented on https://wiki.jenkins-ci.org/display/JENKINS/Administering+Jenkins
• Cancel the process
• Restart Jenkins and again, go to the central configuration
• Observation: the workspace root directory suddenly changed to `${ITEM_ROOTDIR}/workspace`

This behavior is extremely odd and creates a lot of confusion and wastes people's time, as some Jenkins servers/jobs have the one layout, and some have the other layout, depending on when the jobs where created and whether Jenkins was re-started in between or not.