As you may already know, you can use Intune to provide certificates to your clients/end-users for managing access and authentication to your corporate resources (like connecting to a WiFi network using certificate) using the Intune Certificate Connector.
Until now, it was not possible to have more than one connector installed, making it a single point of failure if the server (or the service) hosting the Certificate Connector becomes unavailable.
Since the latest update of Intune, you can now deploy multiple Intune Certificate Connector to make it highly available and implement load balancing to improve the performance.
If you already have deployed one Certificate Connector, there is no need to upgrade it.
To know more about how to deploy and use Intune Certificate Connector you can go there https://docs.microsoft.com/en-us/intune/certficates-pfx-configure