remove backend replica settings

Author: bishal41

articles/iot-operations/troubleshoot/known-issues.md

@@ -42,8 +42,6 @@ This article lists the known issues for Azure IoT Operations.
 
 - MQTT broker resources created in your cluster using Kubernetes aren't visible Azure portal. This is expected because [managing Azure IoT Operations components using Kubernetes is in preview](../deploy-iot-ops/howto-manage-update-uninstall.md#preview-manage-components-using-kubernetes-deployment-manifests), and synchronizing resources from the edge to the cloud isn't currently supported.
 
-- If a Broker only has one backend replica (`backendChain.redundancyFactor` is set to 1) upgrading Azure IoT Operations might fail. Only upgrade Azure IoT Operations if the Broker has more than one backend replica.
-
 - Deployment might fail if the **cardinality** and **memory profile** values are set to be too large for the cluster. To resolve this issue, set the replicas count to `1` and use a smaller memory profile, like `low`.
 
 - Don't publish or subscribe to diagnostic probe topics that start with `azedge/dmqtt/selftest`. Publishing or subscribing to these topics might affect the probe or self-test checks resulting in invalid results. Invalid results might be listed in diagnostic probe logs, metrics, or dashboards. For example, you might see the issue *Path verification failed for probe event with operation type 'Publish'* in the diagnostics-probe logs.