fix dev_mode

Author: reliveyy

images/utils/launcher/config/config.py

@@ -1161,4 +1161,4 @@ def dump_node_attr(node: str, attr: str) -> None:
 
     @property
     def dev_mode(self) -> bool:
-        return self.args.dev
+        return hasattr(self.args, "dev") and self.args.dev