add empty state for runners_laptime

src/Beamershow.svelte

@@ -241,6 +241,9 @@
           >
             {$_("top-laeufer")} ({$_("rundenzeit")})
           </h1>
+          {#if runners_by_laptime.length === 0}
+            <p class="w-full text-center text-3xl">Noch keine Daten...</p>
+          {:else}
             <table class="table p-4 bg-white shadow rounded-lg w-full">
               <thead>
                 <tr>
@@ -286,6 +289,7 @@
                 {/each}
               </tbody>
             </table>
+          {/if}
         </div>
       {:else if current_page === "orgs_distance"}
         <div transition:slide|local>