change lr_decay config field to noam_schedule

train.py

@@ -602,7 +602,7 @@ def main(args):  # pylint: disable=redefined-outer-name
     if num_gpus > 1:
         model = apply_gradient_allreduce(model)
 
-    if c.lr_decay:
+    if c.noam_schedule:
         scheduler = NoamLR(optimizer,
                            warmup_steps=c.warmup_steps,
                            last_epoch=args.restore_step - 1)