Error during the BLS training

[meaten]

Hi,

Thanks for the great codebase!
I run into an error in line 218 of trainer/trainer.py during running train_bls.py.
line 218: poses[baseline] = BASELINES[baseline](x_gt, y_gt, 1)
TypeError: <lambda>() takes 2 positional arguments but 3 were given

Line 218 should be as below to avoid the error.
poses[baseline] = BASELINES[baseline](x_gt, y_gt)

The change is too small, so I didn't do a pull request.
I would appreciate it if you check this!

[meaten]

I want to mention that the error above happens when we specify valid_data_loader.