New license request: LGPL 2.1 with LGPL 2.0 references

**License Homepage URL**

https://github.com/KDE/ktp-presence-dataengine/blob/master/presencesource.cpp

**License Notes**

Mixes LGPL 2.1 and LGPL 2.0 language:

```
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
```

and:

```
* You should have received a copy of the GNU Library General Public
* License along with this program; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
```

Scancode currently doesn't fully recognize it:

```
"license_detections": [
{
"license_expression": "lgpl-2.1-plus",
"license_expression_spdx": "LGPL-2.1-or-later",
"matches": [
{
"license_expression": "lgpl-2.1-plus",
"license_expression_spdx": "LGPL-2.1-or-later",
"from_file": "presencesource.cpp",
"start_line": 6,
"end_line": 19,
"matcher": "3-seq",
"score": 94.17,
"matched_length": 113,
"match_coverage": 94.17,
"rule_relevance": 100,
"rule_identifier": "lgpl-2.1-plus_113.RULE",
"rule_url": "https://github.com/nexB/scancode-toolkit/tree/develop/src/licensedcode/data/rules/lgpl-2.1-plus_113.RULE"
}
],
"identifier": "lgpl_2_1_plus-464aada1-9984-d23e-0694-6671bd1d15a1"
}

```