bpo-40050: Rephrase NEWS entry (GH-19148)

Author: vstinner

Misc/NEWS.d/next/Library/2020-03-24-16-17-20.bpo-40050.6GrOlz.rst

@@ -1,3 +1,3 @@
-Fix ``importlib._bootstrap_external``. Remove two unused imports importlib:
-``_thread`` and ``_weakref``. Avoid creating a new ``winreg`` builtin module if
-it's already available in :data:`sys.modules`.
+Fix ``importlib._bootstrap_external``: avoid creating a new ``winreg`` builtin
+module if it's already available in :data:`sys.modules`, and remove redundant
+imports.