[format.python] disable py code formatting for some hunks of code

Disable the python code formatting from python-black, where the readability of
code suffers by formatting.

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

searx/preferences.py

@@ -325,6 +325,7 @@ class Preferences:
         super().__init__()
 
         self.key_value_settings = {
+            # fmt: off
             'categories': MultipleChoiceSetting(
                 ['general'],
                 is_locked('categories'),
@@ -422,6 +423,7 @@ class Preferences:
                     'False': False
                 }
             ),
+            # fmt: on
         }
 
         self.engines = EnginesSetting('engines', choices=engines)