[#6566] fix indentation

Author: xabbuh

components/options_resolver.rst

@@ -404,10 +404,10 @@ For options with more complicated validation schemes, pass a closure which
 returns ``true`` for acceptable values and ``false`` for invalid values::
 
     
-      // ...
-      $resolver->setAllowedValues('transport', function ($value) {
-          // return true or false
-      });
+    // ...
+    $resolver->setAllowedValues('transport', function ($value) {
+        // return true or false
+    });
 
 In sub-classes, you can use :method:`Symfony\\Component\\OptionsResolver\\OptionsResolver::addAllowedValues`
 to add additional allowed values without erasing the ones already set.