Revert "Fix all Python Cookbook links (#22205)" (GH-22424)

This commit reverts commit ac0333e1e117b7f61ed7ef1dbcdb6e515ada603b as the original links are working again and they provide extended features such as comments and alternative versions.
diff --git a/Lib/test/test_math.py b/Lib/test/test_math.py
index 2abe5b0..a6f6483 100644
--- a/Lib/test/test_math.py
+++ b/Lib/test/test_math.py
@@ -611,7 +611,7 @@
         def msum(iterable):
             """Full precision summation.  Compute sum(iterable) without any
             intermediate accumulation of error.  Based on the 'lsum' function
-            at https://github.com/ActiveState/code/tree/master/recipes/Python/393090_Binary_floating_point_summatiaccurate_full/recipe-393090.py
+            at http://code.activestate.com/recipes/393090/
 
             """
             tmant, texp = 0, 0