Move “export” before decorators

As this is what upstream does.

See also https://github.com/tc39/proposal-decorators/issues/69

app/javascript/flavours/glitch/features/public_timeline/index.js

@@ -25,9 +25,9 @@ const mapStateToProps = (state, { onlyMedia, columnId }) => {
   };
 };
 
-@connect(mapStateToProps)
+export default @connect(mapStateToProps)
 @injectIntl
-export default class PublicTimeline extends React.PureComponent {
+class PublicTimeline extends React.PureComponent {
 
   static defaultProps = {
     onlyMedia: false,