Fix collections ABC deprecation notice

The deprecation originally slated for 3.9 was deferred to 3.10
(bpo-39674, pythonGH-18545). However the deprecation notice in the release
was left as is, and still indicates deprecation with 3.9.

Also add a missing space in the message.

Author: Anthchirp

Lib/collections/__init__.py

@@ -47,8 +47,8 @@ def __getattr__(name):
         obj = getattr(_collections_abc, name)
         import warnings
         warnings.warn("Using or importing the ABCs from 'collections' instead "
-                      "of from 'collections.abc' is deprecated since Python 3.3,"
-                      "and in 3.9 it will stop working",
+                      "of from 'collections.abc' is deprecated since Python 3.3, "
+                      "and in 3.10 it will stop working",
                       DeprecationWarning, stacklevel=2)
         globals()[name] = obj
         return obj