Fix support of python 3.9

import hmac

import hashlib

from urllib.parse import urlencode

from flask_babel import gettext

from searx import settings

from urllib.parse import urlencode

name = gettext('Rest API')

            <h2>{{_("Page not found")}}</h2>

            {% autoescape false %}

            <p>{{ _('Go to %(search_page)s.', search_page=unicode('<a href="{}">{}</a>').format(url_for('index'), _('search page'))) }}</p>

            <p>{{ _('Go to %(search_page)s.', search_page='<a href="{}">{}</a>'.format(url_for('index'), _('search page'))) }}</p>

            {% endautoescape %}

        </div>

    </div>