Fixed broken link (#3007)

Author: LarryOsterman

sdk/eventhubs/azure_messaging_eventhubs_checkpointstore_blob/README.md

@@ -169,4 +169,4 @@ Azure SDK for Rust is licensed under the [MIT](https://github.com/Azure/azure-sd
 [Source code]: https://github.com/Azure/azure-sdk-for-rust/tree/main/sdk/eventhubs/azure_messaging_eventhubs_checkpointstore_blob/src
 [CONTRIBUTING.md]: https://github.com/Azure/azure-sdk-for-rust/blob/main/CONTRIBUTING.md
 [Code of Conduct FAQ]: https://opensource.microsoft.com/codeofconduct/faq/
-[default_cred_ref]: https://docs.rs/azure_identity/latest/azure_identity/struct.DefaultAzureCredential.html
+[default_cred_ref]: https://docs.rs/azure_identity/latest/azure_identity/struct.DeveloperToolsCredential.html