res/lang-selector::fixed selector maybe has not sky animation of background

resolve:
    use setTimeout to execute init() function in sky.js

reason:
    when document.body.onload=init ,the canvas in three.js perhaps will not ready.

tower:https://tower.im/members/6440fe0bf4f944baa5c5e99137a521e8/?me=1

Change-Id: I29b73c10be63ffe85e864cb80c51f2a2156f18f3