Issue #16190: fix random module recommendation to use ssl.RAND_bytes().

Doc/library/random.rst

@@ -45,9 +45,9 @@ from sources provided by the operating system.
 
 .. warning::
 
-   The generators of the :mod:`random` module should not be used for security
-   purposes. Use :func:`ssl.RAND_bytes` if you require a cryptographically
-   secure pseudorandom number generator.
+   The pseudo-random generators of this module should not be used for
+   security purposes.  Use :func:`os.urandom` or :class:`SystemRandom` if
+   you require a cryptographically secure pseudo-random number generator.
 
 
 Bookkeeping functions: