The notice you get should not prevent page from working. It is caused because you try to access uploaded file when there is no file uploaded (or not by using 'imagem-noticia' input). This can be fixed changing this:
$imagem = $_FILES["imagem-noticia"];
$destino = "../img/noticias/".$imagem['name'];
To:
if (isset($_FILES["imagem-noticia"])) {
$imagem = $_FILES["imagem-noticia"];
$destino = "../img/noticias/".$imagem['name'];
}
New code makes sure that file ais uploaded before trying to perform further operations with it.