display stream if avaliable

_includes/post-event.html

@@ -22,6 +22,9 @@
       <br><p>Es findet keine Aufzeichnung statt.</p>
       {% endif %}
       <br>
+      {% if event.stream %}
+      <p>Stream: <a href={{event.stream}}>{{event.stream}}</a></p><br>
+      {% endif %}
       <b>Raum:</b>
       {% for location in event.locations %}
       {{ location | xml_escape }} <br>