App: key QR by content (again)

src/App.svelte

@@ -190,11 +190,11 @@
     {/if}
     <div class="d-flex justify-content-center align-items-stretch m-1"
 	 class:invisible={!lnurl}>
-      <!-- {#key lnurl} -->
+      {#key lnurl}
       <a href="lightning:{lnurl}">
 	<QR value={lnurl} size="{230}" />
       </a>
-      <!-- {/key} -->
+      {/key}
     </div>
     <div class="btn-group flex-wrap mt-auto mb-2"
 	 role="group" class:invisible={!lnurl}>