Multisite request – Add support for optional constant for key/secret

Could you please add support for the recaptcha key and secret to be added as a constant to wp-config.php instead of needing to be in the database. It makes it a lot easier for large multisites that share a domain.

Eg. replace get_option() in your plugin with a custom function that first checks for a constant like CAPTCHA_PUBLIC and CAPTCHA_PRIVATE