Minor RSS output whitespace reduction (#7969)

fix https://github.com/FreshRSS/FreshRSS/issues/7968

app/views/index/rss.phtml

@@ -3,9 +3,8 @@
 	/** @var FreshRSS_View $this */
 ?>
 <?= '<?xml version="1.0" encoding="UTF-8" ?>'; ?>
-<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:media="http://search.yahoo.com/mrss/"
-	<?= $this->rss_base == '' ? '' : ' xml:base="' . $this->rss_base . '"' ?>
->
+<rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:media="http://search.yahoo.com/mrss/" <?=
+	$this->rss_base === '' ? '' : ' xml:base="' . $this->rss_base . '"' ?>>
 	<channel>
 		<title><?= $this->rss_title ?></title>
 		<link><?= $this->html_url ?></link>