Suggestion on page 444

[baifanhorst]

At the bottom of page 444, a pytorch lightning trainer class instance is created as:

if torch.cuda.is_available():
trainer = pl.Trainer(max_epochs=10, gpus=1)
else:
trainer = pl.Trainer(max_epochs=10)

However, in the latest version, it should be changed to

if torch.cuda.is_available():
trainer = pl.Trainer(max_epochs=10, accelerator="gpu", devices=1)
else:
trainer = pl.Trainer(max_epochs=10)