fix(Preview): reorder encodings for detection

Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>

Author: susnux

lib/private/Preview/SVG.php

@@ -89,7 +89,7 @@ public function getThumbnail(File $file, int $maxX, int $maxY): ?IImage {
 	 */
 	protected function canBeProcessed(string $content): bool {
 		// check for allowed encodings and convert if necessary
-		$encoding = mb_detect_encoding($content, ['UTF-8', 'ISO-2022-JP', 'ISO-8859-1'], true);
+		$encoding = mb_detect_encoding($content, ['ISO-2022-JP', 'UTF-8', 'ISO-8859-1'], true);
 		if ($encoding === false) {
 			return false;
 		} elseif ($encoding !== 'UTF-8') {