i18n system can create error when updating i18n database via "update"

Created by: GVogeler

When clicking on Update Now in http://monasterium.net/mom/translate?lang=deu&catalog=all&only-untranslated=true&key=&q=&id=tag:www.monasterium.net,2011:/mom/widget/charter MOM-CA returns a Error while updating catalogues message.

The error is created in mom-ca/my/XRX/src/core/app/i18n/widget/translate.widget.xml when triggering the service update-i18n-catalog (which is inherited from core and uses the function catalog:update() from catalog.xqm ) by executing the xforms submission in https://github.com/icaruseu/mom-ca/blob/57134ff12dc83234e9c32e62889378d6a364381e/my/XRX/src/core/app/i18n/widget/translate.widget.xml#L367