I see. It looks like you’re running into an old bug we had, which was fixed back in January:
https://github.com/discourse/discourse/commit/b0088361a474575a4fcd3fbef77d9fa0286ef113
This fix hasn’t been backported to the stable branch, so I’m afraid you’ll either have to update to tests-passed, or wait for the next stable release. In the meantime, the warning you see can be safely ignored - the browser will automatically remove the query component of the URL.