perf:chart组件增加设置随机颜色方法

tip:当线条过多，默认颜色数量不够时须使用此方法

nezha-fronted/src/components/common/pickTime.vue

@@ -171,7 +171,7 @@
       selectInterval(val) {
         this.visible = false;
         clearInterval(this.intervalTimer);
-        if (val) {
+        if (val && val.value != -1) {
           this.interval = val;
           const start = new Date(this.searchTime[1]);
           const now = new Date();