Remove reference to SigV4 issue

A dead link has been removed in `README.md`.

README.md

@@ -979,7 +979,7 @@ It is recommended to use the default value for `max_samples_per_send` in Prometh
 # Caveats
 
 ### Unsupported SigV4 Authentication
-Prometheus supports SigV4 for the `remote_write` protocol with limitations and lacks SigV4 support for the `remote_read` protocol. With the deployment method of the `Prometheus Connector` being a lambda function, the `service` portion of the SigV4 header must be set to the value `execute-api`. Prometheus hard-codes this value to `aps`, limiting SigV4 support to Amazon Managed Service for Prometheus. Integrating SigV4 support will require `remote_read` SigV4 support added and configuration settings for the `service` portion of the SigV4 header integrated with [Prometheus](https://github.com/prometheus/prometheus). See [issue 1](https://github.com/awslabs/amazon-timestream-connector-prometheus/issues/33) for tracking the integration of this feature with the `Prometheus Connector`, and please leave a comment if this is a feature you wish to be added to the repository.
+Prometheus supports SigV4 for the `remote_write` protocol with limitations and lacks SigV4 support for the `remote_read` protocol. With the deployment method of the `Prometheus Connector` being a lambda function, the `service` portion of the SigV4 header must be set to the value `execute-api`. Prometheus hard-codes this value to `aps`, limiting SigV4 support to Amazon Managed Service for Prometheus. Integrating SigV4 support will require `remote_read` SigV4 support added and configuration settings for the `service` portion of the SigV4 header integrated with [Prometheus](https://github.com/prometheus/prometheus).
 
 If SigV4 is required, SigV4 authentication is possible by running Prometheus with a [sidecar](https://github.com/awslabs/aws-sigv4-proxy). This will require enabling IAM authentication for the APIGateway deployment, which is not covered in the `Prometheus Connector` documentation.