update NEWS entry

methane · methane · commit d3de551f515e · 2019-09-12T20:16:42.000+09:00
diff --git a/Misc/NEWS.d/next/Library/2019-08-29-18-48-48.bpo-37587.N7TGTC.rst b/Misc/NEWS.d/next/Library/2019-08-29-18-48-48.bpo-37587.N7TGTC.rst
@@ -1,2 +1,2 @@
-Use ``_PyUnicodeWriter`` instead of list of unicode chunks in
-``_json.scanstring``. Decoding long non-ASCII string is up to 4x faster.
+``_json.scanstring`` is now up to 4x faster when there are many backslash
+escaped characters in the JSON string.
