Comment 1 for bug 1578051

Very likely to be a bug in my patch, which was supposed to have zero effect, except for improving the error messages, but it looks like this scenario wasnt covered in the tests (the inverse scenario was covered, as you've found).

https://github.com/pyflakes/pyflakes/commit/aec68a7847d8dbd1371242f42f9302103a68178f