TrainLoraNode: cannot access local variable 'multi_res' where it is not associated with a value

### Custom Node Testing

- [x] I have tried disabling custom nodes and the issue persists (see [how to disable custom nodes](https://docs.comfy.org/troubleshooting/custom-node-issues#step-1%3A-test-with-all-custom-nodes-disabled) if you need help)

### Expected Behavior

train the lora

### Actual Behavior

### Steps to Reproduce

run

### Debug Logs

```powershell
loaded completely; 95367431640625005117571072.00 MB usable, 5913.57 MB loaded, full load: True
!!! Exception during processing !!! cannot access local variable 'multi_res' where it is not associated with a value
Traceback (most recent call last):
File "/home/rodrigoandrigo/Notebooks/ComfyUI/execution.py", line 510, in execute
output_data, output_ui, has_subgraph, has_pending_tasks = await get_output_data(prompt_id, unique_id, obj, input_data_all, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, hidden_inputs=hidden_inputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/rodrigoandrigo/Notebooks/ComfyUI/execution.py", line 324, in get_output_data
return_values = await _async_map_node_over_list(prompt_id, unique_id, obj, input_data_all, obj.FUNCTION, allow_interrupt=True, execution_block_cb=execution_block_cb, pre_execute_cb=pre_execute_cb, hidden_inputs=hidden_inputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/rodrigoandrigo/Notebooks/ComfyUI/execution.py", line 292, in _async_map_node_over_list
await process_inputs(input_data_all, 0, input_is_list=input_is_list)
File "/home/rodrigoandrigo/Notebooks/ComfyUI/execution.py", line 286, in process_inputs
result = f(**inputs)
^^^^^^^^^^^
File "/home/rodrigoandrigo/Notebooks/ComfyUI/comfy_api/internal/__init__.py", line 149, in wrapped_func
return method(locked_class, **inputs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/rodrigoandrigo/Notebooks/ComfyUI/comfy_api/latest/_io.py", line 1275, in EXECUTE_NORMALIZED
to_return = cls.execute(*args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/rodrigoandrigo/Notebooks/ComfyUI/comfy_extras/nodes_train.py", line 614, in execute
real_dataset=latents if multi_res else None,
^^^^^^^^^
UnboundLocalError: cannot access local variable 'multi_res' where it is not associated with a value
```

### Other

_No response_