[Glitch] Use the new JSX transform everywhere

Port 8f66126b10 to glitch-soc

app/javascript/flavours/glitch/features/compose/components/dropdown.jsx

@@ -1,7 +1,7 @@
 //  Package imports.
 import classNames from 'classnames';
 import PropTypes from 'prop-types';
-import React from 'react';
+import { PureComponent } from 'react';
 import Overlay from 'react-overlays/Overlay';
 
 //  Components.
@@ -9,7 +9,7 @@ import { IconButton } from 'flavours/glitch/components/icon_button';
 import DropdownMenu from './dropdown_menu';
 
 //  The component.
-export default class ComposerOptionsDropdown extends React.PureComponent {
+export default class ComposerOptionsDropdown extends PureComponent {
 
   static propTypes = {
     isUserTouching: PropTypes.func,