Undo bad author merge

A bad author merge cannot be reversed and is subsequently preventing the reversal of bad work/edition edits.

### Evidence / Screenshot (if possible)

### Relevant url?
https://openlibrary.org/recentchanges/2014/04/04/merge-authors/47986246

### Steps to Reproduce

1. Go to ...https://openlibrary.org/recentchanges/2014/04/04/merge-authors/47986246
2. Do ...Undo All

* Actual: Sorry. There seems to be a problem with what you were just looking at.

We've noted the error 2021-09-16/091434108530 and will look into it as soon as possible. Head for home?
* Expected: Merge should be reversed.

### Details

- **Logged in (Y/N)?**
- **Browser type/version?**
- **Operating system?**
- **Environment (prod/dev/local)?** prod

### Proposal & Constraints

### Related files

### Stakeholders

@cdrini @mekarpeles @jimchamp