We don't need to set this value. In commit f2ef27d3 I made a mistake
thinking `Globalize.locale` and `I18n.locale` should always be in sync,
but they're actually automatically in sync when `Globalize.locale` is
`nil`.
So the best way to avoid any issues is not to assign `Globalize.locale`,
and use `Globalize.with_locale` where necessary instead.