doc: fix a typo in a date for version 13.2.0

PR-URL: #30587
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Beth Griggs <Bethany.Griggs@uk.ibm.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

doc/changelogs/CHANGELOG_V13.md

@@ -33,7 +33,7 @@
   * [Archive](CHANGELOG_ARCHIVE.md)
 
 <a id="13.2.0"></a>
-## 2019-21-19, Version 13.2.0 (Current), @MylesBorins
+## 2019-11-21, Version 13.2.0 (Current), @MylesBorins
 
 ### Notable Changes