fix function _internalPick's return when using thinInstanceEnablePicking and pickWithBoundingInfo
fix function _internalPick's return when using thinInstanceEnablePicking and pickWithBoundingInfo

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