HISTORY.md: mention new parameter

Author: daviddrysdale

python/HISTORY.md

@@ -12,6 +12,12 @@ This file does not generally include descriptions of patch releases (vX.Y.Z
 changes.  (Metadata updates are best checked
 [upstream](https://github.com/google/libphonenumber/blob/master/release_notes.txt).)
 
+
+What's new in 9.0.23
+--------------------
+
+Extra `min_candidate_length` parameter to `PhoneNumberMatcher`.
+
 What's new in 9.0.0
 --------------------