update changelog for bug fix
## 1.39.0
* Feature - Add support for bulk loading env vars through environmentFiles field in task definition [#2420](https://github.com/aws/amazon-ecs-agent/pull/2420)
* Feature - Add v4 task metadata endpoint, which includes additional network information compared to v3 [#2396](https://github.com/aws/amazon-ecs-agent/pull/2396)
+* Bug - Fixed an edge case that can cause task failed to start when using container ordering success condition [#2404](https://github.com/aws/amazon-ecs-agent/pull/2404).
## 1.38.0
* Feature - add integration with EFS's access point and IAM authorization features; support EFS volume for task in awsvpc network mode
