Changed url to PHP-CS-FIXER repository
minor #4554 Changed url to PHP-CS-FIXER repository (jzawadzki)

This PR was submitted for the master branch but it was merged into the 2.3 branch instead (closes #4554).

Discussion
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Changed url to PHP-CS-FIXER repository

I've updated php-cs-fixer links as it's moved to FriendsOfPHP

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets | -

Commits
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332b6d4 Changed url to PHP-CS-FIXER repository