minor #7518 [Yaml] fix dump arguments (xabbuh)

This PR was merged into the 3.2 branch.

Discussion
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[Yaml] fix dump arguments

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852c0c0 [Yaml] fix dump arguments

Author: xabbuh

components/yaml.rst

@@ -276,7 +276,7 @@ flag::
 Similarly you can use ``DUMP_EXCEPTION_ON_INVALID_TYPE`` when dumping::
 
     $data = new \stdClass(); // by default objects are invalid.
-    Yaml::dump($data, Yaml::DUMP_EXCEPTION_ON_INVALID_TYPE); // throws an exception
+    Yaml::dump($data, 2, 4, Yaml::DUMP_EXCEPTION_ON_INVALID_TYPE); // throws an exception
 
     echo $yaml; // { foo: bar }