Update conv2d_gradfix.py

[angelv-salazar]

Update allow version of Pytorch to 1.10

i had this error whe run the train: stylegan conv2d_gradfix not supported on PyTorch 1.10.0+cu111

So it works without the warning when the version 1.10 is add to:

if any(torch.version.startswith(x) for x in ['1.7.', '1.8.', '1.9', '1.10.']): in line 53