update CHANGELOG.md

Author: nicholasgribanov

CHANGELOG.md

@@ -6,7 +6,8 @@ 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](https://github.com/open-telemetry/opentelemetry-python/compare/v1.10.0-0.29b0...HEAD)
-
+- `opentelemetry-instrumentation-tornado` Fix Tornado errors mapping to 500
+  ([#1048])(https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1048)
 ### Fixed
 
 - `opentelemetry-instrumentation-urllib` make span attributes available to sampler