Renaming a hidden sub-job of a master job, breaks the history for the master job

[elblinkin]

1. add a job as a hidden sub-job of a master build
2. trigger a couple of master builds
3. rename the hidden sub-job and update the master build with the new name
4. observe that all balls have now turned grey on the master project
5. click through on a job with a grey ball and observe that the renamed sub-project is not displayed (a broken image is shown instead)