Fix bug

src/populate.py

@@ -23,11 +23,11 @@ def get_inspect_log_url(model_name: str, benchmark_name: str) -> str:
     with open("./inspect_log_file_names.json", "r") as f:
         inspect_log_files = json.load(f)
     log_file_name = inspect_log_files[model_name].get(benchmark_name, None)
-    # replace .json with .eval
-    log_file_name = log_file_name.replace(".json", ".eval")
     if log_file_name is None:
         return ""
     else:
+        # replace .json with .eval
+        log_file_name = log_file_name.replace(".json", ".eval")
         return f"https://storage.googleapis.com/inspect-evals/{model_name}/index.html?log_file=logs/logs/{log_file_name}"