Añadir configuración para Django 3.x
The default value of the X_FRAME_OPTIONS setting was changed on Django 3.0 from SAMEORIGIN to DENY. SummernoteWidget requires 'SAMEORIGIN'. See * [Clickjacking Protection](https://docs.djangoproject.com/en/3.0/ref/clickjacking/) * <https://github.com/summernote/django-summernote/commit/3d44a3ab1758a1a412e9f582bf71be9ec31ee547#diff-04c6e90faac2675aa89e2176d2eec7d8>