Convert the card resource to a string if necessary
Convert the card resource to a string if necessary

Apparently the fetched column can be a string or resource. Hence we have
to catch the resource type and convert it to a string.

Signed-off-by: Christoph Wurst <7abde52c298496fa169fb750f91f213a282142af@winzerhof-wurst.at>

nextcloud/server,nextcloud/server,nextcloud/server,nextcloud/server