Stats query doesn't work if a collection has no group
When executing the query for the statistics page, an exception is thrown when a collection with no group exists in ace
Exception Description: The column result [colgroup] was not found in the results of the query.
Query: ResultSetMappingQuery(sql="SELECT l1.date, c.name, c.colgroup, m.count, m.size FROM logevent l1 JOIN ( SELECT collection_id, min(date) AS date FROM logevent WHERE logtype = 20 GROUP BY collection_id) AS l2 ON l1.collection_id = l2.collection_id AND l1.date = l2.date AND l1.logtype = 20 JOIN ( SELECT id, name, colgroup FROM collection ) AS c ON l1.collection_id = c.id JOIN ( SELECT count(id) AS count, sum(size) AS size, parentcollection_id FROM monitored_item GROUP BY parentcollection_id) AS m ON m.parentcollection_id = c.id ")