BUG: fixes formatted value error for missing sheet (#27676)
Fixes a formatted message at [io.excel._odfreader line 62](https://github.com/pandas-dev/pandas/blob/master/pandas/io/excel/_odfreader.py#L63)

- [x] closes #27676
- [x] tests added / passed
- [x] passes `black pandas`
- [ ] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`
- [x] whatsnew entry
