[mod] searxng_extras - minor improvements

- fix docs/searxng_extra/standalone_searx.py.rst
- add SPDX tag
- pylint standalone_searx.py and update_wikidata_units.py

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

searxng_extra/standalone_searx.py

@@ -1,5 +1,11 @@
 #!/usr/bin/env python
-"""Script to run searx from terminal.
+# lint: pylint
+
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# (C) Copyright Contributors to the SearXNG project.
+# (C) Copyright Contributors to the searx project (2014 - 2021)
+
+"""Script to run SearXNG from terminal.
 
 Getting categories without initiate the engine will only return `['general']`
 
@@ -56,25 +62,8 @@ Example to run it from python:
     },
     "suggestions": [...]
 }
-"""  # noqa: E501
-# pylint: disable=pointless-string-statement
-'''
-searx is free software: you can redistribute it and/or modify
-it under the terms of the GNU Affero General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+""" # pylint: disable=line-too-long
 
-searx is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-GNU Affero General Public License for more details.
-
-You should have received a copy of the GNU Affero General Public License
-along with searx. If not, see < http://www.gnu.org/licenses/ >.
-
-(C) 2016- by Alexandre Flament, <alex@al-f.net>
-'''
-# pylint: disable=wrong-import-position
 import argparse
 import sys
 from datetime import datetime