minor #11784 [HttpClient] Fixed missing parenthesis (jmsche)

This PR was merged into the 4.3 branch.

Discussion
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[HttpClient] Fixed missing parenthesis

Fixed missing parenthesis in Progress callback example

Commits
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7c2e9b0 [HttpClient] Fixed missing parenthesis

Author: javiereguiluz

components/http_client.rst

@@ -290,7 +290,7 @@ called when new data is uploaded or downloaded and at least once per second::
             // $dlSize is the total size to be downloaded or -1 if it is unknown
             // $info is what $response->getInfo() would return at this very time
         },
-    ];
+    ]);
 
 Any exceptions thrown from the callback will be wrapped in an instance of
 ``TransportExceptionInterface`` and will abort the request.