fix type while create table with UUID column

This PR is inspired by [this](https://github.com/playframework/play-slick/issues/203) issue.

I'm not sure it's necessary to do it at all, but if it's relevant, then I can make backports to any branches you would tell.

Also if something is missing, I'm glad to fix it.

Thanks in advance.

Cheers, Nick.
This seems to be obviously true, because that's what the driver uses. This test would even pass, if you would not add your change, so it is not testing your change. We should test this somehow differently. Going via codegen may be a solution.