That’s the problem–end of wp-config.php.

I put the define right after define(‘DB_COLLATE’, ”);

The key is, it has to go before this line:

require_once(ABSPATH . 'wp-settings.php');

I did this and it worked. Now I don’t know if this matters or not, but for mine I added a comment before the code, like so…

/** Switch off Post Revisions */
define('WP_POST_REVISIONS', false);

I went into my posts and checked and all the autosaves are gone.