I have developed a plugin for myself and was using it for a little and after decided to go public. But the plugin got declined after submission and code review with the reason ##Calling core loading files directly. I fixed already all issues they mentioned, but only one bothering me now. I have `require_once( ABSPATH.'/wp-admin/includes/upgrade.php' );` in few places to use dbDelta(), but if I will remove `require_once` declaration I won't be able to use dbDelta(). Do you think it will be an issue with second code review? Any developer who already did and released their plugins?