[mod] pylint all files with one profile / drop PYLINT_SEARXNG_DISABLE_OPTION

In the past, some files were tested with the standard profile, others with a
profile in which most of the messages were switched off ... some files were not
checked at all.

- ``PYLINT_SEARXNG_DISABLE_OPTION`` has been abolished
- the distinction ``# lint: pylint`` is no longer necessary
- the pylint tasks have been reduced from three to two

  1. ./searx/engines -> lint engines with additional builtins
  2. ./searx ./searxng_extra ./tests -> lint all other python files

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

searx/plugins/hash_plugin.py

@@ -1,25 +1,11 @@
-'''
-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.
+# SPDX-License-Identifier: AGPL-3.0-or-later
+# pylint: disable=missing-module-docstring
 
-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) 2015 by Adam Tauber, <asciimoo@gmail.com>
-(C) 2018, 2020 by Vaclav Zouzalik
-'''
-
-from flask_babel import gettext
 import hashlib
 import re
 
+from flask_babel import gettext
+
 name = "Hash plugin"
 description = gettext("Converts strings to different hash digests.")
 default_on = True
@@ -30,7 +16,7 @@ query_examples = 'sha512 The quick brown fox jumps over the lazy dog'
 parser_re = re.compile('(md5|sha1|sha224|sha256|sha384|sha512) (.*)', re.I)
 
 
-def post_search(request, search):
+def post_search(_request, search):
     # process only on first page
     if search.search_query.pageno > 1:
         return True
@@ -40,7 +26,7 @@ def post_search(request, search):
         return True
 
     function, string = m.groups()
-    if string.strip().__len__() == 0:
+    if not string.strip():
         # end if the string is empty
         return True