preservePreferenceDefault('http_header_frame_options', 'n'); $installer->preservePreferenceDefault('http_header_xss_protection', 'n'); $installer->preservePreferenceDefault('http_header_content_type_options', 'n'); $installer->preservePreferenceDefault('http_header_content_security_policy', 'n'); $installer->preservePreferenceDefault('http_header_strict_transport_security', 'n'); $installer->preservePreferenceDefault('http_header_public_key_pins', 'n'); }