Unbind cluster module should be disabled on the Host Cluster page

Created by: serenashe

Describe the bug In a multi-cluster environment, there's an option for users to Unbind Cluster on the basic information page of the host cluster. After this operation is performed, the host cluster is unbound for a few seconds, and then reappears.

The following screenshot shows the issue:

Versions used(KubeSphere/Kubernetes) KubeSphere: v3.1.0 Kubernetes: v1.18.3

Environment Multi-cluster environment 3 masters: 8cpu/8g 3 nodes: 8cpu/16g

To Reproduce Steps to reproduce the behavior:

1. Log in to the KubeSphere console and go to the host cluster.
2. On the left navigation pane, click Cluster Settings > Basic Information.
3. On the basic information page of the host cluster, select the checkbox on the left of I confirm to unbind the cluster., and then click Unbind.
4. The host cluster is unbound for a few seconds, and then reappears.

Expected behavior The host cluster cannot be unbound as it will be re-created and then reappears. On the basic information page of the host cluster in a multi-cluster environment, the Unbind Cluster module should be disabled.

Please take a look, thanks :)