bug 881195: WIFI status not correctly displayed in the init process of Settings

https://bugzilla.mozilla.org/show_bug.cgi?id=881195

In the init process of Settings, the wifi status always show "offline" by default which will cause some confusion just like the pic attanchment of bug 881195.
By delete the l10n id of wifi status, the wifi status shows blank in the init process, after the init process, wifi status will display correctly just like the "Call settings" and "Cellular and Data"