resolver for published private collections does not work anymore

Created by: GVogeler

http://www.monasterium.net/mom/IlluminierteUrkunden/collection returns an XRX error:

err:XPTY0004 xs:boolean(true) is not a sub-type of xs:string [at line 369, column 9, source: /db/XRX.live/mom/app/xrx/resolver.xqm]
In function:
	resolver:is-mycollection-existing(xs:string*)