fix undefined index files_data in cli env

Author: samsonasik

src/Handler/Logging.php

@@ -199,7 +199,7 @@ private function sendMail(int $priority, string $errorMessage, array $extra, str
         $this->mailMessageService->setFrom($this->emailSender);
         $this->mailMessageService->setSubject($subject);
 
-        $filesData = $extra['request_data']['files_data'];
+        $filesData = $extra['request_data']['files_data'] ?? [];
         foreach ($this->emailReceivers as $email) {
             $this->mailMessageService->setTo($email);
             $writer    = new Writer\Mail(