Don't display image in extension chip if iconURI undefined

src/views/preview/extension-chip.jsx

@@ -5,10 +5,12 @@ require('./extension-chip.scss');
 
 const ExtensionChip = props => (
     <div className={classNames('extension-chip', {'has-status': props.hasStatus})}>
+        {props.iconURI &&
             <img
                 className="extension-icon"
                 src={props.iconURI}
             />
+        }
         <div className="extension-content">
             <span>{props.extensionName}</span>
             {props.hasStatus && (