Fix loss of values in multi-valued fieds after restoring a draft

Please use the jars in the first comment to reproduce with the following scenario:

1. Navigate to a Workspace
2. Click the New button and choose Fiche d'indexation
3. Set the title to Fiche 1
4. Add 2 Auteur and 2 Victime items and fill every suggestion field
5. Create the document
6. Click on the Edit tab
7. Set a description
8. Leave the Edit form by clicking on the parent in the left tree: a draft is created and an alert is displayed: Leave anyway
9. Go back to the document, then to the Edit tab
10. In the top right corner, the system indicates that a draft was saved: use it
11. The description is automatically filled with the old value
12. Save the document

=> Observe that there is only 1 Auteur and 1 Victime now

The bug was reproduced against 7.10 and 9.10