query notifications by status return null

[suzhengwei]

when querying notifications by statuses, it returns null. The request returns 200, and no useful information in the api log. In fact, there are lot of eligible notifications in DB. When querying notifications with no status, it returns all notifications.

example:

request:
GET http://*:15868/v1/notifications?status=finished,failed,error

respone:
{'notifications':[]}