After changing the language, we were checking that certain content isn't
there.
However, the content wasn't there before changing the language either,
so the test will pass even if the request to change the language hasn't
finished.
Although this is probably OK because we aren't changing the language
using an AJAX request, and so Capybara will correctly wait until the
request is finished before finishing the test, confirming that the page
has changed after a request is something we try to do in every test.
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