post mr fixes

src/ApiResources/Organization/Subdomain/SubdomainAvailability.php

@@ -1,4 +1,5 @@
 <?php
+declare (strict_types=1);
 
 namespace App\ApiResources\Organization\Subdomain;
 

src/Repository/Organization/SubdomainRepository.php

@@ -29,13 +29,11 @@ class SubdomainRepository extends ServiceEntityRepository
      */
     public function getActiveSubdomainOf(Organization $organization): ?Subdomain {
         $qb = $this->createQueryBuilder('subdomain');
-        $results = $qb
+        return $qb
                 ->where('subdomain.organization = :organization')
                 ->andWhere($qb->expr()->eq('subdomain.active', true))
                 ->setParameter('organization', $organization)
                 ->getQuery()
-                ->getResult();
-
-        return $results[0] ?? null;
+                ->getOneOrNullResult();
     }
 }