Use a canonical way to specify python

Be consistent with other scripts in the same directory.

This also improves portability as less hardcoded full path of
python interpreter.

Change-Id: I605710035de2c7c85b5996238af18b3c6b0955ef

tools/jenkins-projects-checks.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#! /usr/bin/env python
 
 # Copyright 2014 SUSE Linux Products GmbH
 #