If you can’t update your PyTorch version on the server, you could try to remove these keys before loading them in your old PyTorch version:
model = nn.Sequential(
    nn.Conv2d(3, 6, 3, 1, 1),
    nn.BatchNorm2d(6),
    nn.ReLU()
)

# Save in new PyTorch version
torch.save(model.state_dict(), 'bn.pth')

# Load in old version
model = ...
state_dict = torch.load('bn.pth')
del state_dict['1.num_batches_tracked']
model.load_state_dict(state_dict)

Just adapt the code to your layer names.