backend_type was added to the CVS log output in commit 70a7b477.

Reported-by: Fabrízio de Royes Mello

Discussion: https://postgr.es/m/CAFcNs+ruvRks3BV1j7yQ-MvxsswmKJa0cVh2yK5Dd-xXVM8wPw@mail.gmail.com

Backpatch-through: master