Update changelog.

Author: nedtwigg

jvm/CHANGELOG.md

@@ -11,6 +11,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Fixed
+- Off-by-one in the error message for a VCR key mismatch. ([#526](https://github.com/diffplug/selfie/pull/526))
 
 ## [2.5.1] - 2025-03-04
 ### Fixed