sysstat: show cpu-cores at false by default

Assets/settings-widgets-default.json

@@ -156,7 +156,7 @@
       "useMonospaceFont": true,
       "usePadding": false,
       "showCpuUsage": true,
-      "showCpuCores": true,
+      "showCpuCores": false,
       "showCpuFreq": false,
       "showCpuTemp": true,
       "showGpuTemp": false,

Services/System/SystemStatService.qml

@@ -1161,15 +1161,17 @@ Singleton {
       root.coresUsage = new Array(nbCores).fill(0);
 
     let coresStats = [];
+    let newCoresUsage = root.coresUsage.slice();
     for (let i = 0; i < nbCores; i++) {
       const coreCpuLine = lines[i + 1];
       const currCoreStats = calculateLineUsage(coreCpuLine);
       const coreUsage = computeUsage(root.prevCpuCoresStats?.[i], currCoreStats);
       if (coreUsage >= 0) {
-        root.coresUsage[i] = coreUsage;
+        newCoresUsage[i] = coreUsage;
       }
       coresStats.push(currCoreStats);
     }
+    root.coresUsage = newCoresUsage;
     root.prevCpuCoresStats = coresStats;
   }