Wrong list item number on changing list level

1. add ordered list items with 2 levels
2. make sure last item is level 2
3. chaging last item to level 1 with shift+tab works fine, but deleting until getting back to level 1  ends up with a wrong item number

```markdown
1. hello
    1. hi
    2. how
    3. are
4. you // this should be 2
```