fixed thumbnails for lectures without titlefile set

templates/macros.html

@@ -168,7 +168,7 @@ $('#embedcodebtn').popover(
 {% macro lecture_list_item(lecture,videos,global_permissions) %}
 <li class="list-group-item" id="lecture-{{lecture.id}}">
 	<div class="row">
-		<div style="background-image: url('{% if not lecture.titlefile %}{{url_for('static',filename='no-thumbnail.png')}}{% else %}{{ config.VIDEOPREFIX }}/thumbnail/l_{{lecture.id}}.jpg'){% endif %}" class="col-sm-2 col-xs-12 thumbnailimg">
+		<div style="background-image: url('{{ config.VIDEOPREFIX }}/thumbnail/l_{{lecture.id}}.jpg')" class="col-sm-2 col-xs-12 thumbnailimg">
 		{% if not videos|length is equalto 0 %}
 			<a href="{{url_for('lecture', course=lecture.course.handle, id=lecture.id)}}">
 				<span class="glyphicon glyphicon-play-circle playpreviewbtn"></span>