bug #14301 [FrameworkBundle][Translation] skip warmUp when cache is not used. (aitboudad)

This PR was merged into the 2.7 branch.

Discussion
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[FrameworkBundle][Translation] skip warmUp when cache is not used.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Fixed tickets  | #13942
| Tests pass?   | yes
| License       | MIT

Commits
-------

efb10f6 [FrameworkBundle][Translation] skip warmUp when cache is not used.

src/Symfony/Bundle/FrameworkBundle/Translation/Translator.php

@@ -77,6 +77,11 @@ class Translator extends BaseTranslator implements WarmableInterface
      */
     public function warmUp($cacheDir)
     {
+        // skip warmUp when translator doesn't use cache
+        if (null === $this->options['cache_dir']) {
+            return;
+        }
+
         foreach ($this->resourceLocales as $locale) {
             $this->loadCatalogue($locale);
         }