minor #12794 Fix build error (OskarStark)

This PR was merged into the 4.4 branch.

Discussion
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Fix build error

> Warning, treated as error:
> /home/travis/build/symfony/symfony-docs/components/phpunit_bridge.rst:313: WARNING: Mismatch: both interpreted text role prefix and reference suffix.

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Commits
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1d6eeb2 Fix build error

Author: OskarStark

components/phpunit_bridge.rst

@@ -311,7 +311,7 @@ Deprecation Notices at Autoloading Time
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 By default, the PHPUnit Bridge uses ``DebugClassLoader`` from the
-:doc:`ErrorHandler component </components/error_handler>`_ to throw deprecation
+:doc:`ErrorHandler component </components/error_handler>` to throw deprecation
 notices at class autoloading time. This can be disabled with the
 ``debug-class-loader`` option.