Add changelog entry

Author: sroda

CHANGELOG.md

@@ -16,6 +16,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Fix SQLAlchemy uninstrumentation
+  ([#1581](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1581))
 - Fix aiopg instrumentation to work with aiopg < 2.0.0
   ([#1473](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1473))
 - `opentelemetry-instrumentation-aws-lambda` Adds an option to configure `disable_aws_context_propagation` by