Merge pull request 'allow error string to be null in case the password was correct' (#39) from bugfix/account-cannot-be-deleted into develop

Reviewed-on: https://gitea.e5tv.hu/esoko/mapguesser/pulls/39
Reviewed-by: Pőcze Bence <bence@pocze.ch>

src/Controller/UserController.php

@@ -210,7 +210,7 @@ class UserController implements ISecured
         return new JsonContent(['success' => true]);
     }
 
-    private function confirmUserIdentity(User $user, ?DateTime $authenticatedWithGoogleUntil, ?string $password, string &$error): bool
+    private function confirmUserIdentity(User $user, ?DateTime $authenticatedWithGoogleUntil, ?string $password, ?string &$error): bool
     {
         if ($authenticatedWithGoogleUntil !== null && $authenticatedWithGoogleUntil > new DateTime()) {
             return true;