Minor fix to label smoothing

Add option to change label smoothing for model initialization from a checkpoint file.

casanovo/denovo/model_runner.py

@@ -242,6 +242,7 @@ def initialize_model(self, train: bool) -> None:
             top_match=self.config.top_match,
             n_log=self.config.n_log,
             tb_summarywriter=self.config.tb_summarywriter,
+            train_label_smoothing=self.config.train_label_smoothing,
             warmup_iters=self.config.warmup_iters,
             max_iters=self.config.max_iters,
             lr=self.config.learning_rate,