Given a Jenkins setup, with a single master that has the labels value set to <labels value>.

• Manage Jenkins ->
• Manage Nodes ->
• master "Configure" ->
• Set Labels to <labels value> ->
• Save

When I edit other System settings

• Manage Jenkins ->
• Configure System ->
• Save (no changes are required)

Then my <labels value> should still be in the <label>-element in the config.xml file.