remove duplicate

frontend/src/routes/+page.svelte

@@ -47,10 +47,10 @@
 
     // update device date
     let now = Date.now();
-    let clear;
+    let interval;
     $: {
-        clearInterval(clear);
-        clear = setInterval(() => {
+        clearInterval(interval);
+        interval = setInterval(() => {
             now = Date.now();
         }, 1000);
     }

frontend/src/routes/settings/+page.svelte

@@ -185,7 +185,6 @@
 </script>
 
 <div class="container">
-    <DeviceForm bind:device={newDevice} mode="add" />
     <section class="m-0 mt-4 p-4 shadow-sm">
         <form on:submit|preventDefault={saveSettings}>
             <h3 class="mb-3">Ping interval</h3>