NetworkMenu/NMDeviceWireless: use the device state instead of active connection state

Since we connect to signals for that, we need to sync on that, or
we can miss a notification.

https://bugzilla.gnome.org/show_bug.cgi?id=709043

js/ui/status/network.js

@@ -1064,7 +1064,8 @@ const NMDeviceWireless = new Lang.Class({
     },
 
     getIndicatorIcon: function() {
-        if (this._device.active_connection.state == NetworkManager.ActiveConnectionState.ACTIVATING)
+        if (this._device.state >= NetworkManager.DeviceState.PREPARE &&
+            this._device.state < NetworkManager.DeviceState.ACTIVATED)
             return 'network-wireless-acquiring-symbolic';
 
         let ap = this._device.active_access_point;