Fix generated avatars and nophoto cache files

Since nextcloud/server#19493 newFile() by default does not write the file anymore.
Setting an empty string as content will make it write the file immediate,
without having to call putContent() afterwards.

Signed-off-by: Joas Schilling <coding@schilljs.com>

apps/dav/lib/CardDAV/PhotoCache.php

@@ -108,7 +108,7 @@ class PhotoCache {
 		$data = $this->getPhoto($card);
 
 		if ($data === false || !isset($data['Content-Type'])) {
-			$folder->newFile('nophoto');
+			$folder->newFile('nophoto', '');
 			return;
 		}
 
@@ -116,7 +116,7 @@ class PhotoCache {
 		$extension = self::ALLOWED_CONTENT_TYPES[$contentType] ?? null;
 
 		if ($extension === null) {
-			$folder->newFile('nophoto');
+			$folder->newFile('nophoto', '');
 			return;
 		}
 

lib/private/Avatar/UserAvatar.php

@@ -252,7 +252,7 @@ class UserAvatar extends Avatar {
 			$avatar->putContent($data);
 			$ext = 'png';
 
-			$this->folder->newFile('generated');
+			$this->folder->newFile('generated', '');
 			$this->config->setUserValue($this->user->getUID(), 'avatar', 'generated', 'true');
 		}