No 'Access-Control-Allow-Origin' header

I embedded a third-party javascript script into a page. It's for tracking the events from a video on the page. But I get an error:

 XMLHttpRequest cannot load http://ift.tt/1ymKKAA. 
 No 'Access-Control-Allow-Origin' header is present on the requested resource. 
 Origin 'http://fast.wistia.net' is therefore not allowed access.

I know there're the solutions to that error but they, probably, would be applicable if it were my own script.

For some reason I believe it has to do with the settings on my web server which is apache. So I added this to /etc/apache2/sites-enabled/my_domain.com but it didn't help.

<VirtualHost *:80>
    Access-Control-Allow-Origin: "http://fast.wistia.net"`

I also tried adding Access-Control-Allow-Origin: "*" but yet it didn't pan out.

How do I fix the error?