Switch to side-by-side view

--- a/src/filters/rcldjvu.py
+++ b/src/filters/rcldjvu.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python2
 # Copyright (C) 2016 J.F.Dockes
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by