Resolve "Fix PWA offline fallback page"

Closes #324 (closed)

aleksis/core/templates/offline.html

@@ -2,6 +2,8 @@
 
 {% load i18n %}
 
+{% block browser_title %}{% blocktrans %}Network error{% endblocktrans %}{% endblock %}
+
 {% block content %}
   <h3><i class="material-icons left medium" style="font-size: 2.92rem;">signal_wifi_off</i>{% blocktrans %}No internet
     connection.{% endblocktrans %}</h3>