Connecting more than 1 cluster is not possible

[mrCherry97]

Description
As a user, I want to connect 2-3 kubeconfigs and have them available in Busola. After connecting the second cluster, the first one is removed.

Expected result
The user is able to connect and see more than 1 cluster in Busola.

Actual result
The user can connect to only one cluster.

Steps to reproduce

1. Connect one cluster
2. Go to Clusters List
3. Click Connect cluster
4. Paste kubeconfig to the second cluster
5. Click Next
6. Click Connect
7. Go to Clusters List
8. Check how many clusters are present in the list

Troubleshooting