Fix for strict standards error in declaration of Rewrite_Rules_Inspector_List_Table::single_row()

The current code causes an error in strict standards mode due to the method signature of `Rewrite_Rules_Inspector_List_Table::single_row()` not matching the parent `WP_List_Table::single_row($item)`.

I am running PHP 5.4.17 and the error is visible when WordPress debug mode is turned on.

This is the error thrown:

> Strict standards: Declaration of Rewrite_Rules_Inspector_List_Table::single_row() should be compatible with WP_List_Table::single_row($item) in ... /wp-content/plugins/rewrite-rules-inspector/rewrite-rules-inspector.php on line 298

I have fixed this by reverting the signature to a single `$item` to match the parent and passing the additional `$rule` information as an additional array entry in `$rewrite_data`