AssertionError description typo

[goodsuga]

Hi! I think there's a typo:

if torch.is_floating_point(output) and threshold is None:
        raise ValueError(
            f"Output should be one of the integer types if ``threshold`` is not None, got {output.dtype}."
        )

in metrics/functional.py:121

Shouldn't it be "when threshold is None"?

if torch.is_floating_point(output) and threshold is None:
        raise ValueError(
            f"Output should be one of the integer types if ``threshold`` is None, got {output.dtype}."
        )