[checkpoint logic] Fix bug which doesn't account for NoneType for `model.hparams` (#1817)
[checkpoint logic] Fix bug which doesn't account for NoneType for `model.hparams` (#1817)

The intention of the code is to output a warning message when `hparams`
is null or not set. Instead the code now fatals when
`model.hparams = None`. Prevent that.
williamFalcon/pytorch-lightning,williamFalcon/pytorch-lightning