[Validator] Test DNS Email constraints using checkdnsrr() mock

Author: nicolas-grekas

phpunit.xml.dist

@@ -30,7 +30,7 @@
         <listener class="Symfony\Bridge\PhpUnit\SymfonyTestsListener">
             <arguments>
                 <array>
-                    <element><string>Symfony\Component\HttpFoundation</string></element>
+                    <element key="time-sensitive"><string>Symfony\Component\HttpFoundation</string></element>
                 </array>
             </arguments>
         </listener>