Update description

    def test_opensearch_xml(self):

        result = self.app.get('/opensearch.xml')

        self.assertEqual(result.status_code, 200)

        self.assertIn('<Description>Search searx</Description>', result.data)

        self.assertIn('<Description>a privacy-respecting, hackable metasearch engine</Description>', result.data)

    def test_favicon(self):

        result = self.app.get('/favicon.ico')