Port of mk-add-old-attachments-to-uploads-table to EE
What does this MR do?
Port of mk-add-old-attachments-to-uploads-table to EE. Resolves conflict in which I backported the which
method from EE to CE.
CE MR: https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/15270
Edited by Michael Kozono