Update app.py

app.py

@@ -31,7 +31,7 @@ def add_new_eval(
     upload_content = input_file
     submission_repo = Repository(local_dir=SUBMISSION_NAME, clone_from=SUBMISSION_URL, use_auth_token=HF_TOKEN, repo_type="dataset")
     submission_repo.git_pull()
-    filename = now.strftime("%Y%m%d_%H%M%S")
+    filename = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
     now = datetime.datetime.now()
     with open(f'{filename}.zip','wb') as f:
         f.write(input_file)