'NoneType' object has no attribute 'load_state_dict'

[thuvh]

if model is None, we will catch an error as in the title

https://github.com/xinntao/Real-ESRGAN/blob/a4abfb2979a7bbff3f69f58f58ae324608821e27/realesrgan/utils.py#L70C9-L70C14