minor #10555 fix order of member vars (OskarStark)

This PR was merged into the 4.1 branch.

Discussion
----------

fix order of member vars

<!--

If your pull request fixes a BUG, use the oldest maintained branch that contains
the bug (see https://symfony.com/roadmap for the list of maintained branches).

If your pull request documents a NEW FEATURE, use the same Symfony branch where
the feature was introduced (and `master` for features of unreleased versions).

-->

Commits
-------

92f23cf fix order of member vars

Author: javiereguiluz

components/messenger.rst

@@ -175,8 +175,8 @@ First, create your sender::
 
     class ImportantActionToEmailSender implements SenderInterface
     {
-       private $toEmail;
        private $mailer;
+       private $toEmail;
 
        public function __construct(\Swift_Mailer $mailer, string $toEmail)
        {