fix memory bloat on restore

train.py

@@ -569,7 +569,7 @@ def main(args):  # pylint: disable=redefined-outer-name
         pos_weight=torch.tensor(10)) if c.stopnet else None
 
     if args.restore_path:
-        checkpoint = torch.load(args.restore_path)
+        checkpoint = torch.load(args.restore_path, map_location='cpu')
         try:
             # TODO: fix optimizer init, model.cuda() needs to be called before
             # optimizer restore