Fix #1646 : Unable to mount collections
Merge pull request #871 from romainneutron/fix-1646

[3.8] Fix #1646 : Unable to mount collections
Merge branch '3.8'

Conflicts:
	lib/Alchemy/Phrasea/Controller/Admin/Databox.php
	lib/classes/collection.php
	templates/web/admin/databox/databox.html.twig