Re: [Twisted-Python] Python 3: Odd failure to print unhandled error tb

My guess is that since `d` is at the global scope, it doesn't get garbage collected until some unfortunately late phase in the interpreter tear-down where maybe stderr isn't even available any more. Here be dragons.

I'd definitely ignore this case for now and fix the others, which are much more serious, and tractable to fix ;). That's where I've been leaning, so I'll avoid this case for now. I'll probably reference this in #7927 for completeness.

Thanks! -Jason