Fixes #2308: Custom fields panel absent from object view in UI

netbox/templates/inc/custom_fields_panel.html

@@ -1,4 +1,4 @@
-{% with custom_fields=obj.custom_fields %}
+{% with custom_fields=obj.get_custom_fields %}
     {% if custom_fields %}
         <div class="panel panel-default">
             <div class="panel-heading">