bug #17774 [Translation] fix wrong information (kbond)

This PR was merged into the 6.1 branch.

Discussion
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[Translation] fix wrong information

Ref: #16727 (comment)

Commits
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87a2dc2 [Translation] fix wrong information

Author: OskarStark

translation.rst

@@ -853,7 +853,8 @@ of:
 
 * All the services that are tagged with ``kernel.locale_aware``;
 * ``\Locale::setDefault()``;
-* If a request is available, the ``_locale`` request attribute::
+* If the ``RequestContext`` service is available, the ``_locale``
+  parameter (so urls are generated with the new locale)::
 
     use Symfony\Component\Translation\LocaleSwitcher;