reports/ : Use pull/123/commits/deadbeef

[jayvdb]

For the GitHub links, I think it is more usefull to link to repo/pull/123/commits/deadbeef , as this gives the PR and the commit , and also shows big purple merged at the top.

Otherwise, if only linking to repo/commit/deadbeef , ir only shows "master" as the branch to verify that it is a merged commit.