As much as possible, remove dependence on python 2.5
diff --git a/tools/pylibopenflow/bin/pyopenflow-load-controller.py b/tools/pylibopenflow/bin/pyopenflow-load-controller.py
old mode 100755
new mode 100644
index aef34f7..715a73a
--- a/tools/pylibopenflow/bin/pyopenflow-load-controller.py
+++ b/tools/pylibopenflow/bin/pyopenflow-load-controller.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2.5
+#!/usr/bin/env python
 """This script fakes as n OpenFlow switch and
 load the controller with k packets per second.