MAPG-142 modify UserConfirmationRepository to return only one confirmation for user

(it is not possible for an user to have multiple)

src/Controller/UserController.php

@@ -184,7 +184,8 @@ class UserController implements ISecured
 
         \Container::$dbConnection->startTransaction();
 
-        foreach ($this->userConfirmationRepository->getByUser($user) as $userConfirmation) {
+        $userConfirmation = $this->userConfirmationRepository->getByUser($user);
+        if ($userConfirmation !== null) {
             $this->pdm->deleteFromDb($userConfirmation);
         }
 

src/Repository/UserConfirmationRepository.php

@@ -1,8 +1,6 @@
 <?php namespace MapGuesser\Repository;
 
-use Generator;
 use MapGuesser\Database\Query\Select;
-use MapGuesser\Interfaces\Database\IResultSet;
 use MapGuesser\PersistentData\Model\User;
 use MapGuesser\PersistentData\Model\UserConfirmation;
 use MapGuesser\PersistentData\PersistentDataManager;
@@ -29,11 +27,11 @@ class UserConfirmationRepository
         return $this->pdm->selectFromDb($select, UserConfirmation::class);
     }
 
-    public function getByUser(User $user): Generator
+    public function getByUser(User $user): ?UserConfirmation
     {
         $select = new Select(\Container::$dbConnection);
         $select->where('user_id', '=', $user->getId());
 
-        yield from $this->pdm->selectMultipleFromDb($select, UserConfirmation::class);
+        return $this->pdm->selectFromDb($select, UserConfirmation::class);
     }
 }