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/ui/components/onboarding_modal.js

@@ -159,9 +159,9 @@ const mapStateToProps = state => ({
   domain: state.getIn(['meta', 'domain']),
 });
 
-@connect(mapStateToProps)
+export default @connect(mapStateToProps)
 @injectIntl
-export default class OnboardingModal extends React.PureComponent {
+class OnboardingModal extends React.PureComponent {
 
   static propTypes = {
     onClose: PropTypes.func.isRequired,