Make shebangs Gentoo Prefix friendly
See also: https://blogs.gentoo.org/mgorny/2016/02/08/a-quick-note-on-portable-shebangs/

--- a/thinkhdaps.py
+++ b/thinkhdaps.py
@@ -1,4 +1,4 @@
-#!@PYTHON@
+#!/usr/bin/env python2
 # Copyright (c) 2008-2009  Thomas Pani <thomas.pani@gmail.com>
 # based on an awn applet Copyright (c) 2008  onox <denkpadje@gmail.com>
 #