Update region if it has changed after rendering footer (bug 1066774)

Follow-up to #663 
https://bugzilla.mozilla.org/show_bug.cgi?id=1066774

We do wait for the consumer info promise before triggering 'navigate', so the region in the views is OK, but the footer can be rendered before that.


There is another optional parameter, specific to regions, to ignore geoip when calling that method. And others properties, like carrier, don't even have a default, although I suppose we could use `''`.