fix "Enter VR" when stats are not shown (fixes MozVR/aframe#164)
fix "Enter VR" when stats are not shown (fixes MozVR/aframe#164)

chenzlabs/aframe,dmarcos/aframe,wizgrav/aframe,MatthewShotton/aframe,aframevr/aframe-core,aframevr/aframe,jaxmolina/ar,chenzlabs/aframe,fernandojsg/aframe,weddingdj/aframe,mkungla/aframe,RSpace/aframe,weddingdj/aframe,MatthewShotton/aframe,aframevr/aframe,dmarcos/aframe,aframevr/aframe-core,googlecreativelab/aframe,RSpace/aframe,jaxmolina/ar,googlecreativelab/aframe,msimpson/aframe,jzitelli/aframe,wizgrav/aframe,ngokevin/aframe,msimpson/aframe,darkwing/aframe,ngokevin/aframe,mkungla/aframe,fernandojsg/aframe,darkwing/aframe,jzitelli/aframe