Fixes validateSrc description to remove selector references
Fixes validateSrc description to remove selector references

mkungla/aframe,dmarcos/aframe,googlecreativelab/aframe,wizgrav/aframe,RSpace/aframe,chenzlabs/aframe,fernandojsg/aframe,googlecreativelab/aframe,jaxmolina/ar,jaxmolina/ar,darkwing/aframe,ngokevin/aframe,weddingdj/aframe,weddingdj/aframe,aframevr/aframe,aframevr/aframe,dmarcos/aframe,chenzlabs/aframe,wizgrav/aframe,darkwing/aframe,ngokevin/aframe,fernandojsg/aframe,mkungla/aframe,RSpace/aframe