Correct subjects "Dance" subtopic

When you add the "Art/Dance" subject to a document if you use the diff action to compare files, the subject comes with danse and it should be dance

How to reproduce

• go to webUI
• edit a file by adding the subject Art/Dance
• go to the Compare action
• subjects shows danse (error)

on github -> https://github.com/nuxeo/nuxeo/blob/master/nuxeo-features/nuxeo-platform-forms-layout-io-plugins/src/test/resources/directories/subtopic.csv