All that you need to do is append ?download=1 to the end of that link. So:
https://copy.com/olQgPNxCpvJhHyrE?download=1
What you have there isn't a "direct" link, because it does not take you to an empty page with the download popping up automatically.
After you have updated your modpack download link, ensure that you click on the "versions" tab and update the version to, for example, 1.1 (with a changelog, anything will do).