Fix broken schedule.xml format

closes #1685

src/pretalx/agenda/templates/agenda/schedule.xml

@@ -15,7 +15,7 @@
         <time_zone_name>{{ event.timezone }}</time_zone_name>
         {% if event.color %}<color>{{ event.color }}</color>{% endif %}
         {% for track in event.tracks.all %}
-        <track name="{{ track.name }}" slug="{{ track.slug }}" {% if track.color %} color="{{ track.color.lower }}"{% endif %}>{% if talk.submission.track %}{{ talk.submission.track.name }}{% endif %} />
+        <track name="{{ track.name }}" slug="{{ track.slug }}" {% if track.color %} color="{{ track.color.lower }}"{% endif %}{% if talk.submission.track %}{{ talk.submission.track.name }}{% endif %} />
         {% endfor %}
     </conference>
     {% for day in data %}<day index='{{ day.index }}' date='{{ day.start.date|date:"c" }}' start='{{ day.start|date:"c" }}' end='{{ day.end|date:"c" }}'>