Fix activity not updating

frontend/src/app/components/angular/tracking-functions.ts

@@ -24,6 +24,15 @@ export namespace AngularTrackingHelpers {
     return _.get(item, 'href');
   }
 
+  export function trackByHrefAndProperty(propertyName:string) {
+    return (i:number, item:HalResource) => {
+      let href = _.get(item, 'href');
+      let prop = _.get(item, propertyName, 'none');
+
+      return `${href}#${propertyName}=${prop}`;
+    };
+  }
+
   export function trackByTrackingIdentifier(i:number, item:any) {
     return _.get(item, 'trackingIdentifier', item && item.href);
   }

frontend/src/app/components/wp-single-view-tabs/activity-panel/activity-entry-info.ts

@@ -55,6 +55,10 @@ export class ActivityEntryInfo {
     return this.activity.href;
   }
 
+  public get version() {
+    return this.activity.version;
+  }
+
   public get isNextDate() {
     return this.date !== this.dateOfPrevious;
   }

frontend/src/app/components/wp-single-view-tabs/activity-panel/activity-tab.component.ts

@@ -42,7 +42,7 @@ import {AngularTrackingHelpers} from "core-components/angular/tracking-functions
 export class WorkPackageActivityTabComponent extends ActivityPanelBaseController implements OnDestroy {
   public workPackage:WorkPackageResource;
   public tabName = this.I18n.t('js.work_packages.tabs.activity');
-  public trackByHref = AngularTrackingHelpers.trackByHref;
+  public trackByHref = AngularTrackingHelpers.trackByHrefAndProperty('version');
 
   constructor(readonly wpCacheService:WorkPackageCacheService,
               readonly $transition:Transition,