Url and title spans are set incorrectly for multiline LinkReferenceDefinition inside a quote block.

For example, for the following markdown:
```
> [foo]:
> /url 'the title'
>
> [foo]
```

Roundtrip renderer, that relies on those spans, produces this:
```
> [foo]:
> /ur' 'the tit'
> 
>[foo]
```