Fastai RNNLearner.classifier wrong size of head of classifier

[jeremy (Jeremy Howard)]

@sgugger

Maybe the problem lies in the is_listy() test and it needs something more general like isinstance(...,Iterable) ?

We actually just closed a PR suggesting that - it would break our code. If we want to test somewhere whether something is iterable, we should simply use isinstance(o,Iterable) or similar.