Explicitly globalize some missing query globals in wp-settings.php

When WordPress is loaded in a function (e.g. unit tests) the variables initialized at the top level aren't globals, but we expect them to be.

Fixes #26867


git-svn-id: https://develop.svn.wordpress.org/trunk@26996 602fd350-edb4-49c9-b593-d223f7449a82