Fix reload swagger error if no arg change previously

Author: calvinhzy

src/aaz_dev/command/controller/workspace_cfg_editor.py

@@ -649,8 +649,9 @@ def inherit_modification(self, ref_cfg: CfgReader):
 
             # inherit arguments modification
             ref_args = []
-            for group in ref_command.arg_groups:
-                ref_args.extend(group.args)
+            if ref_command.arg_groups:
+                for group in ref_command.arg_groups:
+                    ref_args.extend(group.args)
             command.generate_args(ref_args=ref_args)
 
             # inherit outputs