minor #19717 [FrameworkBundle] Remove TranslatorBagInterface check (JhonnyL)

This PR was submitted for the master branch but it was merged into the 2.7 branch instead (closes #19717).

Discussion
----------

[FrameworkBundle] Remove TranslatorBagInterface check

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| BC breaks?    |  no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets |
| License       | MIT
| Doc PR        |

This check is not needed anymore since the existence of TranslatorBagInterface should be guaranteed now.

Commits
-------

fd27801 [FrameworkBundle] Remove TranslatorBagInterface check

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/LoggingTranslatorPass.php

@@ -26,11 +26,6 @@ class LoggingTranslatorPass implements CompilerPassInterface
             return;
         }
 
-        // skip if the symfony/translation version is lower than 2.6
-        if (!interface_exists('Symfony\Component\Translation\TranslatorBagInterface')) {
-            return;
-        }
-
         if ($container->hasParameter('translator.logging') && $container->getParameter('translator.logging')) {
             $translatorAlias = $container->getAlias('translator');
             $definition = $container->getDefinition((string) $translatorAlias);