Update src/Symfony/Component/HttpKernel/Tests/EventListener/RouterProxyListenerTest.php

Just a typo fix
merged branch philipphoffmann/patch-1 (PR #6722)

This PR was merged into the master branch.

Commits
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c1d5f16 Update src/Symfony/Component/HttpKernel/Tests/EventListener/RouterProxyListenerTest.php

Discussion
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Typo fix

Just a typo fix