[FrameworkBundle] Fixed validator factory definition when the Validator API is "auto" for PHP < 5.3.9
bug #11584 [FrameworkBundle] Fixed validator factory definition when the Validator API is "auto" for PHP < 5.3.9 (webmozart)

This PR was merged into the 2.5 branch.

Discussion
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[FrameworkBundle] Fixed validator factory definition when the Validator API is "auto" for PHP < 5.3.9

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11580
| License       | MIT
| Doc PR        | -

Commits
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a74b758 [FrameworkBundle] Fixed validator factory definition when the Validator API is "auto" for PHP < 5.3.9