fix(core-web-video): remove broken css background declaration

Author: mburtch

packages/WebVideo/WebVideo.jsx

@@ -31,7 +31,6 @@ const aspectRatios = {
 const AspectLimiter = styled.div(props => ({
   ...aspectRatios[props.aspectRatio],
   position: 'relative',
-  backgroundImage: `url(${props.aspectRatio})`,
 }))
 
 /**

packages/WebVideo/__tests__/__snapshots__/WebVideo.spec.jsx.snap

@@ -220,7 +220,6 @@ exports[`WebVideo renders 1`] = `
 .c1 {
   padding-top: 56.25%;
   position: relative;
-  background-image: url(16:9);
 }
 
 @media (min-width:768px) {