Are you referring to the international shipping through GSP check box?
If it says that, then you'll ship within the US and it'll be shipped to the buyer through a 3rd party shipper. I'd say just do it, and be mindful that box doesn't get clicked again.
It's also possible that maybe they are using their own 3rd party shipper located in the US.
OTHERWISE, if you did somehow select real international shipping it's really your call on what you want to do.
There's a few boxes you have to fill out for international to work. Like if you are doing a flat price for shipping on locations you choose or based on weight that you have to put in. I'm sort of surprised that would automatically fill out since there's many boxes-- and I tried with my current listings and it wouldn't let me put it through until I put in numbers.
Either way, as a seller *I* would bite the loss because I think that I am responsible for the listings I post. (Usually I'll double check on my phone to catch something odd). But if you feel better canceling it, then you can do that. It's your listing.