How to disable a plugin for certain page?

functions.php file is loaded after the plugins_loaded hook is fired. So you are (probably) removing the hook, but it’s already fired, so it doesn’t really matter.

If you want to remove a hook, you need to know when the hook was added. Then you need to remove the action at a later time, but before that hook is fired.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)