Don't try to checkout matching branches for case of reverts? #56
Description
In case GitHub's revert functionality is used, GitHub will create a branch in the blessed repo with the revert commit in it. Since it's a separate branch, Jenkins will try to find matching branches with the same name in dmd/phobos/dub/utils repositories, and usually it will fail: https://ci.dlang.io/job/dlang-org/job/druntime/job/revert-1879-soreusse/
Perhaps if the branch name starts with revert-* we should still use masters? I don't have high hopes that's configurable in Jenkins though, but who knows.