[charts] Fix chart building

vrobbler/templates/music/track_detail.html

@@ -11,7 +11,7 @@
 <div class="row">
     <p>{{scrobbles.count}} scrobbles</p>
     {% if charts %}
-    <p>{% for chart in charts %}<em><a href="{{chart.link}}">{{chart}}</a></em>{% if forloop.last %}{% else %} | {% endif %}{% endfor %}</p>
+    <p>{% for chart in charts %}<em><a href="{{chart.chart_url}}">{{chart}}</a></em>{% if forloop.last %}{% else %} | {% endif %}{% endfor %}</p>
     {% endif %}
     <div class="col-md">
         <h3>Last scrobbles</h3>