LoadImage returns a 64x64 mask even when there's no mask painted

### Expected Behavior

LoadImage should return "None" for Mask, when no mask is painted

### Actual Behavior

LoadImage returns a 64x64 mask even when there's no mask painted

### Steps to Reproduce

LoadImage -> MaskToImage -> PreviewImage

### Debug Logs

```powershell
n/a
```

### Other

this affects "mask optional" nodes, as I cannot just connect things together, as I _always_ get a mask, even when none is painted.