Update CHANGELOG with a missed bug fix
Ref:
@@ -15,6 +15,7 @@ Kubernetes API Version: 1.15.10
**Bug Fix:**
- Add kubernetes.dynamic to setup.py pkg list [kubernetes-client/python#1096](https://github.com/kubernetes-client/python/pull/1096)
+- Fixed issue in `__del__` method of the `ApiClient` that caused an indefinite hang during garbage collection. [kubernetes-client/python#1073](https://github.com/kubernetes-client/python/pull/1073)
- Fix custom object API example [kubernetes-client/python#1049](https://github.com/kubernetes-client/python/pull/1049)
- Fix deprecation warning in E2E tests [kubernetes-client/python#1036](https://github.com/kubernetes-client/python/pull/1036)
- Use `==/!=` to compare str, bytes, and int literals [kubernetes-client/python#1007](https://github.com/kubernetes-client/python/pull/1007)
