KSES: Remove duplicate object-position property.

As part of some recent changes, the property was added to the list of safe CSS properties twice.

Follow-up to [50634], [50761].

See #52991.

git-svn-id: https://develop.svn.wordpress.org/trunk@50922 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/kses.php

@@ -2248,8 +2248,6 @@ function safecss_filter_attr( $css, $deprecated = '' ) {
 			'margin-left',
 			'margin-top',
 
-			'object-position',
-
 			'padding',
 			'padding-right',
 			'padding-bottom',