When user recreate whole cluster certs, multus thick plugin's previous cert is no longer valid. In such case, we need to prevent to use cert manager's old certs and restart it from bootstrap kubeconfig. This fix reloads client config from bootstrap kubeconfig if cert mgr's cert is failed to load pod.
coverage: 63.18% (-0.5%) from 63.67%
when pulling abe6e05f49d31102c0442dcf602ca4590f99cd57 on s1061123:fix/reload-kubeconfig-if-failed
into 8e5060b9a7612044b7bf927365bbdbb8f6cde451 on k8snetworkplumbingwg:master.
When user recreate whole cluster certs, multus thick plugin's previous cert is no longer valid. In such case, we need to prevent to use cert manager's old certs and restart it from bootstrap kubeconfig. This fix reloads client config from bootstrap kubeconfig if cert mgr's cert is failed to load pod.