Correction for bad issue link in CHANGELOG
The link to issue aws#1919 for release `1.11.596` (2019-07-22) is somewhat garbled, as described in Issue aws#2056.
- Update Apache http client version to `4.5.9`.
- ### Bugfixes
- - Disable apache normalization to handle breaking change introduced in apache httpclient `4.5.7`. See [aws/aws-sdk-java[[#1919](https://github.com/aws/aws-sdk-java/issues/1919)](https://github.com/aws/aws-sdk-java-v2/issues/1919)](https://github.com/aws/aws-sdk-java/issues/1919) for more information.
+ - Disable Apache normalization to handle breaking change introduced in Apache httpclient `4.5.7`. See [aws/aws-sdk-java #1919](https://github.com/aws/aws-sdk-java/issues/1919) for more information.
## __AWS Shield__
- ### Features
