Another strange error

[vdbergh]

https://tests.stockfishchess.org/actions?count=3&before=1637403710.599

This is an assertion error in the conversion to pentanomial which is a bit scary. However it seems that all the Windows workers were affected and no Linux workers. So maybe something was wrong with the windows binary. Unfortunately the pgns don't reveal anything amiss. It would have been nice if the worker would have been able to catch the issue earlier.