fix: ensure user object is available for email reset

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

Author: kesselb

lib/Repair/ResetEmails.php

@@ -39,9 +39,15 @@ public function run(IOutput $output) {
 
 		foreach ($this->guestManager->listGuests() as $guestId) {
 			$guest = $this->userManager->get($guestId);
+			if ($guest === null) {
+				continue;
+			}
+
 			$expectedEmail = $this->config->getUserValue($guestId, Application::APP_ID, 'email', strtolower($guestId));
-			if (strtolower($guest?->getSystemEMailAddress() ?? '') !== $expectedEmail) {
-				$this->config->setUserValue($guestId, 'guests', 'old_email', $guest?->getSystemEMailAddress() ?? '');
+			$currentEmail = $guest->getSystemEMailAddress() ?? '';
+
+			if (strtolower($currentEmail) !== $expectedEmail) {
+				$this->config->setUserValue($guestId, 'guests', 'old_email', $currentEmail);
 				$guest->setSystemEMailAddress($expectedEmail);
 			}
 		}