minor #16269 Correct spelling & grammar in 4.4 controller/ (gnito-org)

This PR was merged into the 4.4 branch.

Discussion
----------

Correct spelling & grammar in 4.4 controller/

<!--

If your pull request fixes a BUG, use the oldest maintained branch that contains
the bug (see https://symfony.com/releases 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 `5.x` for features of unreleased versions).

-->

Commits
-------

0dc86ac Correct spelling & grammar in 4.4 controller/

Author: javiereguiluz

controller/soap_web_service.rst

@@ -95,7 +95,7 @@ buffering the STDOUT and use ``ob_get_clean()`` to dump the echoed output
 into the content of the Response and clear the output buffer. Finally, you're
 ready to return the ``Response``.
 
-Below is an example calling the service using a native `SoapClient`_ client. This example
+Below is an example of calling the service using a native `SoapClient`_ client. This example
 assumes that the ``index()`` method in the controller above is accessible via
 the route ``/soap``::