Fix cannot remove twice from collection

How to reproduce:

• Nuxeo 9.10 (-HF41)
• create 3 documents A,B,C and add them to a collection
• display the collection
• select A and remove A from the collection
• select B and remove B from the collection: this fails

Workaround: display something else then display again the collection and select B and remove B from the collection: this now works, one removal operation at a time

This works fine in 10.10