don't fetch favicon - we don't have it

CHANGELOG

@@ -36,6 +36,7 @@ smasch (1.1.0~alpha.0-1) unstable; urgency=low
   * bug fix: printing mail template failed for general appointments (#435)
   * bug fix: import of csv with subjects did not work with custom fields for
     subjects that existed in db (#415)
+  * bug fix: prevent fetching favicon - we don't have it (#304)
 
 
  -- Piotr Gawron <piotr.gawron@uni.lu>  Thu, 25 Feb 2021 17:00:00 +0200

smash/web/templates/_base.html

@@ -6,6 +6,8 @@
     <title>{% block title %}Scheduling system{% endblock title %}</title>
     <meta content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no" name="viewport">
 
+    <link rel="icon" type="image/png" href="data:image/png;base64,iVBORw0KGgo=">
+
     {% block styles %}
         <!-- Bootstrap 3.3.6 -->
         <link rel="stylesheet" href="{% static 'npm/bootstrap/dist/css/bootstrap.min.css' %}">