Merge pull request #62995 from nextcloud/backport/62919/stable33

[stable33] fix(ObjectStore): reset multipart upload byte counter on retry

Author: AndyScherzinger

lib/private/Files/ObjectStore/S3ObjectTrait.php

@@ -142,10 +142,10 @@ protected function writeMultiPart(string $urn, StreamInterface $stream, array $m
 		$exception = null;
 		$state = null;
 		$size = $stream->getSize();
-		$totalWritten = 0;
 
 		// retry multipart upload once with concurrency at half on failure
 		while (!$uploaded && $attempts <= 1) {
+			$totalWritten = 0;
 			$uploader = new MultipartUploader($this->getConnection(), $stream, [
 				'bucket' => $this->bucket,
 				'concurrency' => $concurrency,