Fix accessible namespaces functionality under restrictive RBAC (#2138)

Signed-off-by: Jari Kolehmainen <jari.kolehmainen@gmail.com>

src/main/cluster.ts

@@ -399,6 +399,8 @@ export class Cluster implements ClusterModel, ClusterState {
     this.accessible = false;
     this.ready = false;
     this.activated = false;
+    this.allowedNamespaces = [];
+    this.accessibleNamespaces = [];
     this.resourceAccessStatuses.clear();
     this.pushState();
   }