[pre-commit.ci] auto fixes from pre-commit.com hooks

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src/wagtail_headless_preview/settings.py

@@ -10,6 +10,7 @@
 This module provides the `headless_preview_settings` object, that is used to access
 the settings. It checks for user settings first, with fallback to defaults.
 """
+
 import warnings
 
 from django.conf import settings