Bug#597609: Bug fixed in upstream

[Antti Haapala]

This bug had been there already when the source code was migrated to Git.
Fixed in
https://github.com/ztane/python-Levenshtein/commit/6c654dad56edf9ba4e38b5ab5f5dd6fcf5fffa54#diff-0113fb946a0ce33f2c5bae10ccd8eca1