bug #11111 Fixed undefined ImageValidator::$suffices property when uploading an image during functional tests (OwlyCode)

This PR was squashed before being merged into the 2.5 branch (closes #11111).

Discussion
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Fixed undefined ImageValidator::$suffices property when uploading an image during functional tests

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11110
| License       | MIT
| Doc PR        |

This will make the FileValidator::$suffices attribute protected so ImageValidator or any inherited class can access it. It fixes #11110 in the most simple way possible.

Commits
-------

859f34e Fixed undefined ImageValidator:: property when uploading an image during functional tests

src/Symfony/Component/Validator/Constraints/FileValidator.php

@@ -160,7 +160,7 @@ class FileValidator extends ConstraintValidator
                 $this->context->addViolation($constraint->maxSizeMessage, array(
                     '{{ size }}'    => $sizeAsString,
                     '{{ limit }}'   => $limitAsString,
-                    '{{ suffix }}'  => static::$suffices[$coef],
+                    '{{ suffix }}'  => self::$suffices[$coef],
                     '{{ file }}'    => $path,
                 ));