Source URL appears to be broken

This hook started failing recently for us, but I'm not sure what is to blame. The source URL in the CloudFormation console does not match this repository:

It links to an non-existent repo [here](https://github.com/aws-cloudformation/example-sse-hook)

However, the code links properly:

Also, this hook was failing on the update of `AWS::RDS::DBCluster`. The `KmsKeyId` configuration is set so encryption can be provided to instances in the cluster. I assume this resource is creating underlying instances on which this hook is run - is that correct?

Start by locating the hook metadata that supplies the CloudFormation console's source URL and compare it with the repository link shown in the issue. Reproduce the update of AWS::RDS::DBCluster with KmsKeyId configured, then verify the source URL points to this repository and clarify whether the hook is invoked for underlying instances.

Written by the indexing model from the issue text.