a8n: Correctly unblock history
Created by: eseliger
This fixes what @christinaforney reported here https://github.com/sourcegraph/sourcegraph/pull/8118#issuecomment-579925273
Created by: eseliger
This fixes what @christinaforney reported here https://github.com/sourcegraph/sourcegraph/pull/8118#issuecomment-579925273