Coding Standards: Fix WPCS indentation issue in `wp-admin/includes/class-wp-links-list-table.php`.

This was causing a `Generic.WhiteSpace.ScopeIndent.IncorrectExact` error if PHP_CodeSniffer 3.4.1 or newer is installed locally, despite the task passing on Travis.

See #49542.
Built from https://develop.svn.wordpress.org/trunk@47595


git-svn-id: https://core.svn.wordpress.org/trunk@47370 1a063a9b-81f0-0310-95a4-ce76da25c4cd