Bug 981219 - [B2G][FTE] The 'Select a Network' page during the FTE does ...

...not show a message when no networks are found
we should also test that we actually show the message on the screen.
An option would be to check that `no-result-container` div that we add on https://github.com/mancas/gaia/blob/bug981219/apps/ftu/js/wifi.js#L298-L303 exists on the DOM.