bug #16695 [SecurityBundle] disable the init:acl command if ACL is not used (Tobion)

This PR was merged into the 2.3 branch.

Discussion
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[SecurityBundle] disable the init:acl command if ACL is not used

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

Related to #16694 but this should go in 2.3 IMO because it was just forgotten. The other acl command already has this logic: https://github.com/symfony/symfony/blob/2.7/src/Symfony/Bundle/SecurityBundle/Command/SetAclCommand.php#L36

It ensures the command list is not flooded with unusable commands.

Commits
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55f84a3 [SecurityBundle] disable the init:acl command if ACL is not used

src/Symfony/Bundle/SecurityBundle/Command/InitAclCommand.php

@@ -23,6 +23,18 @@ use Doctrine\DBAL\Schema\SchemaException;
  */
 class InitAclCommand extends ContainerAwareCommand
 {
+    /**
+     * {@inheritdoc}
+     */
+    public function isEnabled()
+    {
+        if (!$this->getContainer()->has('security.acl.dbal.connection')) {
+            return false;
+        }
+
+        return parent::isEnabled();
+    }
+
     /**
      * {@inheritdoc}
      */