fix for issue bruderstein#115, until switch to python3 is developed

Author: chcg

docs/source/pythonprimer.rst

@@ -131,7 +131,7 @@ Further Information
 
 This guide may be extended in the future, if people request it, and either I get time, or somebody puts some time into it.  There are many good sources of information on the Internet, I've included a couple here.
 
-http://docs.python.org/tutorial/
+http://docs.python.org/2/tutorial/
 
 http://www.tutorialspoint.com/python/python_quick_guide.htm