gpl-1.0-plus false positives

When trying to scan this file with latest scancode, It get the following license :
File from https://github.com/chapel-lang/chapel/blob/master/CHANGES.md
```
{
"key": "gpl-1.0-plus",
"score": 100.0,
"name": "GNU General Public License 1.0 or later",
"short_name": "GPL 1.0 or later",
"category": "Copyleft",
"is_exception": false,
"owner": "Free Software Foundation (FSF)",
"homepage_url": "http://www.gnu.org/licenses/old-licenses/gpl-1.0-standalone.html",
"text_url": "http://www.gnu.org/licenses/old-licenses/gpl-1.0-standalone.html",
"reference_url": "https://enterprise.dejacode.com/urn/urn:dje:license:gpl-1.0-plus",
"spdx_license_key": "GPL-1.0-or-later",
"spdx_url": "https://spdx.org/licenses/GPL-1.0-or-later",
"start_line": 8818,
"end_line": 8820,
"matched_rule": {
"identifier": "gpl_234.RULE",
"license_expression": "gpl-1.0-plus",
"licenses": [
"gpl-1.0-plus"
],
"is_license_text": false,
"is_license_notice": true,
"is_license_reference": false,
"is_license_tag": false,
"matcher": "2-aho",
"rule_length": 3,
"matched_length": 3,
"match_coverage": 100.0,
"rule_relevance": 100.0
},
"matched_text": "- target audience: general public\n\nLicense Changes"
},

```
The context of matched_text is：
```
High-Level Themes
-----------------
- multi-locale task parallelism
- improved task parallel correctness, features, thread management
- improved stability of core features
- very initial/limited support for data parallelism, distributed arrays
- target audience: general public

License Changes
---------------
- switched from MIT to BSD license (see LICENSE)
- updated user agreement text (see AGREEMENT)
```
### Description

gpl-1.0-plus false positives

### How To Reproduce

scancode -li --license-text --json-pp - CHANGES.md.txt

### System configuration

* What OS are you running on? (Windows/MacOS/Linux)
Ubuntu18.04
* What version of scancode-toolkit was used to generate the scan file?
ScanCode 3.2.3
* What installation method was used to install/run scancode? (pip/source download/other)
pip
* Python version
Python 3.6.12