[fix] prepare for pylint 2.14.0

Remove issue reported by Pylint 2.14.0:

- no-self-use: has been moved to optional extension [1]
- The refactoring checker now also raises 'consider-using-generator' messages
  for max(), min() and sum(). [2]

.pylintrc:
  - <option name>-hint has been removed since long, Pylint 2.14.0 raises an
    error on invalid options
  - bad-continuation and bad-whitespace have been removed [3]

[1] https://pylint.pycqa.org/en/latest/whatsnew/2/2.14/summary.html#removed-checkers
[2] https://pylint.pycqa.org/en/latest/whatsnew/2/2.14/full.html#what-s-new-in-pylint-2-14-0
[2] https://pylint.pycqa.org/en/latest/whatsnew/2/2.6/summary.html#summary-release-highlights

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

searx/plugins/__init__.py

@@ -198,7 +198,6 @@ class PluginStore:
         self.plugins.append(plugin)
 
     def call(self, ordered_plugin_list, plugin_type, *args, **kwargs):
-        # pylint: disable=no-self-use
         ret = True
         for plugin in ordered_plugin_list:
             if hasattr(plugin, plugin_type):

searx/plugins/search_on_category_select.py

@@ -18,7 +18,7 @@ from flask_babel import gettext
 
 name = gettext('Search on category select')
 description = gettext(
-    'Perform search immediately if a category selected. ' 'Disable to select multiple categories. (JavaScript required)'
+    'Perform search immediately if a category selected. Disable to select multiple categories. (JavaScript required)'
 )
 default_on = True
 preference_section = 'ui'