update link to pycrypto (closes #12351)

Doc/library/crypto.rst

@@ -27,5 +27,5 @@ Hardcore cypherpunks will probably find the cryptographic modules written by
 A.M. Kuchling of further interest; the package contains modules for various
 encryption algorithms, most notably AES.  These modules are not distributed with
 Python but available separately.  See the URL
-http://www.amk.ca/python/code/crypto.html  for more information.
+http://www.pycrypto.org  for more information.