That's a good question since both versions of the page are visible.
You should probably do a 301 redirect.
You can do a 301 right in the htaccess like:
The "R=301" tells the server to return a 301 status code with the page. The "L" is optional but it tells the server that this is the last rule.
When your finished you can check the results by using a "HTTP Header Viewer" tool. Just search for one on Google.
Leave the gun, take the cannolis.