Detect "All rights reserved." on subsequent line

### Description
We have found a scenario where the copyright is stated on two consecutive lines:

https://github.com/d3/d3-shape/blob/v1.3.7/LICENSE

> Copyright 2010-2015 Mike Bostock
> All rights reserved.

However ScanCode only reports the first line:

```
{
"path": "d3-shape-1.3.7/LICENSE",
"type": "file",
"name": "LICENSE",
"status": "application-package",
...
"copyrights": [
{
"end_line": 1,
"copyright": "Copyright 2010-2015 Mike Bostock",
"start_line": 1
}
],
...
```

### How To Reproduce

Run scancode and check result.

### System configuration

scancode.io with pkg:pypi/scancode-toolkit@32.1.0