Merge pull request #1323 from hwhw/master

only open frontlight device on Kobo devices that actually have light

frontend/device/kobo/powerd.lua

@@ -13,10 +13,12 @@ local KoboPowerD = BasePowerD:new{
 }
 
 function KoboPowerD:init()
+    if self.device.hasFrontlight() then
         local kobolight = require("ffi/kobolight")
         local ok, light = pcall(kobolight.open)
         if ok then self.fl = light end
     end
+end
 
 function KoboPowerD:toggleFrontlight()
     if self.fl ~= nil then