Fix sqlalchemy bug in transfer_get_all_by_project

Because of incorrect use of the sqlalchemy methods joinedload and filter,
incorrect lists of volume transfers were being returned by
transfer_get_all_by_project().

Change-Id: I378a512611591eec896edd5f217e75f9ff0f8ad3
Closes-Bug: 1262432
Merge "Fix sqlalchemy bug in transfer_get_all_by_project"