IoT Hub IP address change notification

To improve availability, reliability and security, IoT Hub will be updating the underlying infrastructure and will go through an internal service update. The update will change the underlying DNS record for IoT Hub, resulting in a change of the IP address. This update will not have any impact if you do not take dependency on IP address. Please follow the best practices for IP addresses by leveraging service tags: [IoT Hub IP Addresses Best Practices](https://docs.microsoft.com/azure/iot-hub/iot-hub-understand-ip-address#best-practices) * Azure IoT Hub * Services * [ Azure IoT Hub](https://azure.microsoft.com/en-gb/products/iot-hub/)