Update train.py comment to 'Model attributes' (#5670)

train.py

@@ -243,7 +243,7 @@ def train(hyp,  # path/to/hyp.yaml or hyp dictionary
     if cuda and RANK != -1:
         model = DDP(model, device_ids=[LOCAL_RANK], output_device=LOCAL_RANK)
 
-    # Model parameters
+    # Model attributes
     nl = de_parallel(model).model[-1].nl  # number of detection layers (to scale hyps)
     hyp['box'] *= 3 / nl  # scale to layers
     hyp['cls'] *= nc / 80 * 3 / nl  # scale to classes and layers