fix(csst_dfs_client): remove redundant error code in connection error handler

csst_dfs_client/common/request.py

@@ -28,7 +28,7 @@ def request_error_handler_decorator(func):
                 return result
             return Result.from_response(result)
         except requests.exceptions.ConnectionError as e:
-            return Result.error(code=502, message= f"Bad Gateway: {e}")
+            return Result.error(message= f"Bad Gateway: {e}")
         except Exception as e:
             return Result.error(message = str(e))
     return wrapper