fix: token check.

main.py

@@ -33,14 +33,14 @@ model = tf.keras.applications.ResNet50(weights="imagenet")
 
 def push_to_hub(hf_token: str, push_dir: str) -> str:
     try:
-        if hf_token is None:
+        if hf_token == "":
             return "### No HF token provided. Model won't be pushed."
         else:
             repo = Repository(local_dir=push_dir, token=hf_token)
             commit_url = repo.push_to_hub()
             return f"### Model successfully pushed: [{commit_url}]({commit_url})"
     except:
-        return f"### {hf_token is None}."
+        return f"### {hf_token == ''}."
 
 
 def post_optimization(list_of_strs: List[str]) -> str: