handle unknown applications more cleanly

src/app/joblist/joblist.component.html

@@ -22,7 +22,7 @@
    </div>
    <mat-divider></mat-divider>
    <div *ngFor="let job of ((identitySubject | async).joblist | async) ; let lastItem = last">
-       <div *ngIf="(appSubject | async).name == job.app.name && job.state == 'Finished'">
+       <div *ngIf="job.app !== null && (appSubject | async).name == job.app.name && job.state == 'Finished'">
         <app-job [jobdata]=job></app-job>
         <mat-divider></mat-divider>
        </div>