a8n: Don't roll back on RunChangesetJob error
Created by: ryanslade
If we roll back the error is never written to the DB and we retry forever.
Fixes https://github.com/sourcegraph/sourcegraph/issues/7759
Created by: ryanslade
If we roll back the error is never written to the DB and we retry forever.
Fixes https://github.com/sourcegraph/sourcegraph/issues/7759