Fix gpu update particle compute after spec changes
Fix gpu update particle compute after spec changes

BabylonJS/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js,RaananW/Babylon.js,RaananW/Babylon.js,sebavan/Babylon.js,BabylonJS/Babylon.js,RaananW/Babylon.js,sebavan/Babylon.js