use instance_name for page title

  <meta name="viewport" content="width=device-width, maximum-scale=1.0, user-scalable=1">

  <meta name="HandheldFriendly" content="True">

  <meta http-equiv="X-UA-Compatible" content="IE=edge, chrome=1">

  <title>{% block title %}{% endblock %}searx</title>

  <title>{% block title %}{% endblock %}{{ instance_name }}</title>

  {% if rtl %}

  <link rel="stylesheet" href="{{ url_for('static', filename='css/searx-rtl.min.css') }}" type="text/css" media="screen" />

  {% else %}