switch to new paywall link

frontend/index.html

@@ -184,7 +184,7 @@
                     <div class="container-fluid">
                         <div class="row row-cols-1 row-cols-lg-1 gy-5 g-lg-1 d-flex justify-content-center text-center flex-fill">
                             <div class="col align-self-center">
-                                <iframe src="https://fsmi.paywall.cs.uni-paderborn.de/" style="height: 90vh;" width="100%" height="100%" frameborder="0" style="border:0;" allowfullscreen="" aria-hidden="false" tabindex="0"></iframe>
+                                <iframe src="http://paywall.localhost" style="height: 90vh;" width="100%" height="100%" frameborder="0" style="border:0;" allowfullscreen="" aria-hidden="false" tabindex="0"></iframe>
                             </div>
                         </div>
                     </div>