Add final intended changes for changelog entry.

CHANGES.rst

@@ -5,7 +5,7 @@ v31.0.0
   with 'setup.py develop'. These .pth files allow
   namespace packages installed by pip or develop to
   co-mingle. This change required the removal of the
-  change for #805, introduced in 28.3.0 and implicated
+  change for #805 and pip #1924, introduced in 28.3.0 and implicated
   in #870, but means that namespace packages not in a
   site packages directory will no longer work on Python
   earlier than 3.5, whereas before they would work on