[BUGFIX] Provide fields that are changed via SendMailServicePrepareAndSendEvent

It is possible to change the email and message in
SendMailServicePrepareAndSendEvent. The results were not passed back
to the SendMailService. This works now.

Related: #1236
(cherry picked from commit e9b9419)

Author: mschwemer

Classes/Domain/Service/Mail/SendMailService.php

@@ -137,6 +137,8 @@ protected function prepareAndSend(array $email): bool
         $event = $this->eventDispatcher->dispatch(
             GeneralUtility::makeInstance(SendMailServicePrepareAndSendEvent::class, $message, $email, $this)
         );
+        $email = $event->getEmail();
+        $message = $event->getMailMessage();
         if ($event->isAllowedToSend() === false) {
             if ($this->settings['debug']['mail']) {
                 $logger = ObjectUtility::getLogger(__CLASS__);