Issues do not appear in closed list if they are labeled with a list label

• Refer to this board: https://gitlab.com/gitlab-org/gitlab-ce/boards/296197?milestone_title=9.3&scope=all&utf8=✓&state=opened&label_name[]=Discussion.
• The issues in this list (https://gitlab.com/gitlab-org/gitlab-ce/issues?scope=all&utf8=✓&state=closed&label_name[]=Discussion&label_name[]=Deliverable&milestone_title=9.3), should appear in the closed column on the board. But they do not, because those issues have the Deliverable label on them.
• All those issues should appear in the closed column on the board.

This requirement was implemented here: https://gitlab.com/gitlab-org/gitlab-ce/issues/24215.