message: frontend: Fix used cores count in cluster health dashboard.
diff: @@ -57,7 +57,7 @@ export const ClusterHealth = () => <div>
  <Gauge title="CPU Usage" query={'sum(rate(node_cpu{mode!="idle"}[2m])) * 100'} />
  <div className="row">
  <div className="col-xs-6">
  - <Scalar title="Used Cores" unit="numeric" query={'cluster:node_cpu:sum_rate5m'} />
  + <Scalar title="Used Cores" unit="numeric" query={'cluster:node_cpu:sum_rate5m * sum(machine_cpu_cores)'} />
  </div>
  <div className="col-xs-6">
  <Scalar title="Total Cores" unit="numeric" query={'sum(machine_cpu_cores)'} />
  