Fixed regression in add_thumbnail_job

sorter.py

@@ -51,7 +51,7 @@ def schedule_thumbnail(lectureid):
 @csrf_protect
 @handle_errors('jobs_overview', 'Zu dieser Veranstaltung existieren keine Videos!', 404, IndexError)
 def add_thumbnail_job():
-	schedule_thumbnail(request.values['lectureid'])
+	schedule_thumbnail(int(request.values['lectureid']))
 	return redirect(request.values.get('ref', url_for('jobs_overview')))
 
 def insert_video(lectureid, dbfilepath, fileformatid, hash="", filesize=-1, duration=-1, sourceid=None):