Avoiding unsafe URL error

src/RunnersMeet.Client/src/app/tracks/track-view/track-view.component.html

@@ -20,5 +20,5 @@
 	<label>Elevation down (m):</label> {{ track.elevationDown }}
 </div>
 <div>
-<iframe [src]="gpxStudioEmbedUrl" width="100%" height="500" frameborder="0" allowfullscreen></iframe>
+	<iframe *ngIf="gpxStudioEmbedUrl" [src]="gpxStudioEmbedUrl" width="100%" height="500" frameborder="0" allowfullscreen></iframe>
 </div>