minor #27115 [Validator] fixes phpdoc reference to an interface that was removed in Symfony 3.0 (hhamon)

This PR was merged into the 3.4 branch.

Discussion
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[Validator] fixes phpdoc reference to an interface that was removed in Symfony 3.0

| Q             | A
| ------------- | ---
| Branch?       | 3.4
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | ~
| License       | MIT
| Doc PR        | ~

Commits
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d2c5813239 [Validator] fixes phpdoc reference to an interface that was removed in Symfony 3.0

Author: nicolas-grekas

ObjectInitializerInterface.php

@@ -14,7 +14,7 @@
 /**
  * Prepares an object for validation.
  *
- * Concrete implementations of this interface are used by {@link ValidationVisitorInterface}
+ * Concrete implementations of this interface are used by {@link Validator\ContextualValidatorInterface}
  * to initialize objects just before validating them.
  *
  * @author Fabien Potencier <fabien@symfony.com>