symfony

This PR was merged into the 2.7 branch.

Discussion
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Remove unused constant

| Q             | A
| ------------- | ---
| Branch?       | 2.7
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | N/A
| License       | MIT
| Doc PR        | N/A

Just a micro clean-up PR, to assimilate the Symfony PR process.
Hope the next one will be more useful 

Commits
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7168d89c Remove unused constant