[Popover] Fix rendering for nested Menus

material-ui/issues/3586 changed `<noscript>` to `<div>`
to resolve an issue with react-event-listener and nested `<noscript>`

That change broke layout for nested Menus. This change fixes that.

src/Popover/Popover.js

@@ -380,7 +380,7 @@ const Popover = React.createClass({
 
   render() {
     return (
-      <div>
+      <div style={{display: 'none'}}>
         <EventListener
           elementName="window"
           onScroll={this.handleScroll}