Fix suggestions selection when editing file

How to reproduce:

• Follow the instructions on the Fashion demo at https://intranet.nuxeo.com/nuxeo/ui/#!/doc/84118793-28e0-4210-88af-7b7d43fa93a4
• in webui create a collection
• create a file and add one of the photos of the file provided in the instructions
• go to edit and remove one of the field suggestions, save.
• go again to edit and try to add the suggestion you removed
• nothing is added and suggestions stays as if it is selected - bug