Merge pull request #3691 from LibreSign/backport/3664/stable29

[stable29] fix: prevent warning when check if array has key

lib/Service/AccountService.php

@@ -409,7 +409,7 @@ private function saveFileOfVisibleElementUsingUser(array $data, IUser $user): Fi
  }
 
  private function saveFileOfVisibleElementUsingSession(array $data, string $sessionId): File {
- if ($data['nodeId']) {
+ if (!empty($data['nodeId'])) {
  return $this->updateFileOfVisibleElementUsingSession($data, $sessionId);
  }
  return $this->createFileOfVisibleElementUsingSession($data, $sessionId);