According to the codex, the define just needs to be before this:
/* That's all, stop editing! Happy blogging. */
require_once(ABSPATH . 'wp-settings.php');
I just added the
to a site of mine that has a private SSL cert, and when I browsed to the site via the non-https URL; e.g., http://mysite.com/wp-login.php it redirected me to the new URL https://mysite.com without the redirect string that yours shows, and that's putting the define for forcing SSL admin right above the line I mention above. If I try to go to the wp-admin folder instead, I get the redirect.
Then, I tried putting the define at the very top of the file, like you say you have it, and it still worked both to wp-admin (with the redirect) and to wp-login (without the redirect).
So I don't think it's something in your .htaccess. It looks like your changes to wp-config.php aren't being paid attention to. Have you verified that the file is actually being copied to the server and that the permissions on the file are correct (644)?
Is your server using any fancy caching software that would account for your modified wp-config.php not being loaded immediately, maybe?