fixes router link, issue on github.com/NativeScript/nativescript-angular/ follows

Author: JohannesHoppe

Diff for: app/book-list/book-list.component.html

@@ -7,7 +7,7 @@
     <StackLayout class="bm-book-list-item item"
         *ngFor="let b of books"
         [book]="b"
-        [nsRouterLink]="b.isbn">
+        [nsRouterLink]="['books', b.isbn]">
     </StackLayout>
     <ActivityIndicator [busy]="!books"></ActivityIndicator>
     <Label *ngIf="books && !books.length" text="Es wurden noch keine Bücher eingetragen."></Label>