SSR: fix graph loading indicators

frontend/src/app/lightning/node-statistics-chart/node-statistics-chart.component.html

@@ -1,7 +1,7 @@
 <div class="full-container">
 
   <div [class]="!widget ? 'chart' : 'chart-widget'" *browserOnly echarts [initOpts]="chartInitOptions" [options]="chartOptions" (chartInit)="onChartInit($event)"></div>
-  <div class="text-center loadingGraphs" *ngIf="isLoading">
+  <div class="text-center loadingGraphs" *ngIf="!stateService.isBrowser || isLoading">
     <div class="spinner-border text-light"></div>
   </div>
 

frontend/src/app/lightning/node-statistics-chart/node-statistics-chart.component.ts

@@ -8,6 +8,7 @@ import { StorageService } from '../../services/storage.service';
 import { download } from '../../shared/graphs.utils';
 import { LightningApiService } from '../lightning-api.service';
 import { ActivatedRoute, ParamMap } from '@angular/router';
+import { StateService } from '../../services/state.service';
 
 @Component({
   selector: 'app-node-statistics-chart',
@@ -48,6 +49,7 @@ export class NodeStatisticsChartComponent implements OnInit {
     @Inject(LOCALE_ID) public locale: string,
     private lightningApiService: LightningApiService,
     private storageService: StorageService,
+    public stateService: StateService,
     private activatedRoute: ActivatedRoute,
   ) {
   }