link to legacy doc on the non-legacy website (#3362)

Author: benjaminp

Doc/library/importlib.rst

@@ -32,7 +32,7 @@ generically as an :term:`importer`) to participate in the import process.
     :ref:`import`
         The language reference for the :keyword:`import` statement.
 
-    `Packages specification <http://legacy.python.org/doc/essays/packages.html>`__
+    `Packages specification <https://www.python.org/doc/essays/packages/>`__
         Original specification of packages. Some semantics have changed since
         the writing of this document (e.g. redirecting based on ``None``
         in :data:`sys.modules`).

Doc/reference/import.rst

@@ -965,7 +965,7 @@ References
 
 The import machinery has evolved considerably since Python's early days.  The
 original `specification for packages
-<http://legacy.python.org/doc/essays/packages.html>`_ is still available to read,
+<https://www.python.org/doc/essays/packages/>`_ is still available to read,
 although some details have changed since the writing of that document.
 
 The original specification for :data:`sys.meta_path` was :pep:`302`, with