Remove irrelevant change from tutorial (sveltejs#241)

Co-authored-by: Lukas Nys <[email protected]>

Author: lukasnys

content/tutorial/01-svelte/07-lifecycle/02-ondestroy/app-b/src/lib/App.svelte

@@ -1,7 +1,7 @@
 <script>
 	import Timer from './Timer.svelte';
 
-	let open = true;
+	let open = false;
 	let seconds = 0;
 
 	const toggle = () => (open = !open);