minor symfony#52319 [DoctrineBridge] Fix exception message (OskarStark)

This PR was merged into the 5.4 branch.

Discussion
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[DoctrineBridge] Fix exception message

| Q             | A
| ------------- | ---
| Branch?       | 5.4
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Issues        | --
| License       | MIT

It is the third, not the second argument.

Commits
-------

5b4961f [DoctrineBridge] Fix exception message

Author: nicolas-grekas

src/Symfony/Bridge/Doctrine/Form/ChoiceList/DoctrineChoiceLoader.php

@@ -40,7 +40,7 @@ public function __construct(ObjectManager $manager, string $class, IdReader $idR
         $classMetadata = $manager->getClassMetadata($class);
 
         if ($idReader && !$idReader->isSingleId()) {
-            throw new \InvalidArgumentException(sprintf('The second argument `$idReader` of "%s" must be null when the query cannot be optimized because of composite id fields.', __METHOD__));
+            throw new \InvalidArgumentException(sprintf('The `$idReader` argument of "%s" must be null when the query cannot be optimized because of composite id fields.', __METHOD__));
         }
 
         $this->manager = $manager;

src/Symfony/Bridge/Doctrine/Tests/Form/ChoiceList/DoctrineChoiceLoaderTest.php

@@ -426,7 +426,7 @@ public function testLoadChoicesForValuesLoadsOnlyChoicesIfValueIsIdReader()
     public function testPassingIdReaderWithoutSingleIdEntity()
     {
         $this->expectException(\InvalidArgumentException::class);
-        $this->expectExceptionMessage('The second argument `$idReader` of "Symfony\\Bridge\\Doctrine\\Form\\ChoiceList\\DoctrineChoiceLoader::__construct" must be null when the query cannot be optimized because of composite id fields.');
+        $this->expectExceptionMessage('The `$idReader` argument of "Symfony\\Bridge\\Doctrine\\Form\\ChoiceList\\DoctrineChoiceLoader::__construct" must be null when the query cannot be optimized because of composite id fields.');
 
         $idReader = $this->createMock(IdReader::class);
         $idReader->expects($this->once())