[Book][Routing] Fixed typo on PHP version of a route definition
minor #3758 [Book][Routing] Fixed typo on PHP version of a route definition (saro0h)

This PR was merged into the 2.3 branch.

Discussion
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[Book][Routing] Fixed typo on PHP version of a route definition

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all (or 2.3+)
| Fixed tickets | -

On http://symfony.com/doc/master/book/routing.html#advanced-routing-example, the PHP version has a wrong route name.

Commits
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b29abca [Book][Routing] Fixed typo on PHP version of a route definition