private collection with copied charters can create cardinality error

Created by: GVogeler

A user collection (my-collection) with copied charters can created an cardinality error:

cardinality error: sequence with more than one item is not allowed here [at line 161, column 26, source: /db/XRX.live/mom/app/collection/mycharters.xqm]
In function:
	mycharters:entries(item()*)

e.g.: http://monasterium.net/mom/7d89914c-c737-4852-8654-cb2bda5c466f/my-collection