fix: Use passed userid when getting attachment folder

Signed-off-by: Julius Härtl <jus@bitgrid.net>

lib/Service/ConfigService.php

@@ -224,7 +224,7 @@ class ConfigService {
 	}
 
 	public function getAttachmentFolder(string $userId = null): string {
-		if ($this->getUserId() === null) {
+		if ($userId === null && $this->getUserId() === null) {
 			throw new NoPermissionException('Must be logged in get the attachment folder');
 		}