minor #5796 Fix for #5783 (BenjaminPaap)

This PR was submitted for the 2.8 branch but it was merged into the 2.3 branch instead (closes #5796).

Discussion
----------

Fix for #5783

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | 2.8
| Fixed tickets | #5783

I can confirm, that this is the only place where the `SplStorageObject` and its methods which were marked as deprecated in symfony/symfony#15907 are referenced.

Commits
-------

065d28c Fix for #5783

Author: xabbuh

components/dom_crawler.rst

@@ -28,9 +28,8 @@ Usage
 The :class:`Symfony\\Component\\DomCrawler\\Crawler` class provides methods
 to query and manipulate HTML and XML documents.
 
-An instance of the Crawler represents a set (:phpclass:`SplObjectStorage`)
-of :phpclass:`DOMElement` objects, which are basically nodes that you can
-traverse easily::
+An instance of the Crawler represents a set of :phpclass:`DOMElement` objects,
+which are basically nodes that you can traverse easily::
 
     use Symfony\Component\DomCrawler\Crawler;