Fix case of empty package directory under usethis tool import-linter#1227

nathanjmcdougall merged 1 commit intomainusethis-python/usethis-python:mainfrom

1226-fatal-crash-on-usethis-tool-import-linterusethis-python/usethis-python:1226-fatal-crash-on-usethis-tool-import-linterCopy head branch name to clipboard