Fix import order with ESLint

Port d27216dc46 to glitch-soc

app/javascript/flavours/glitch/components/column_header.jsx

@@ -1,8 +1,11 @@
-import { PureComponent } from 'react';
 import PropTypes from 'prop-types';
+import { PureComponent } from 'react';
 import { createPortal } from 'react-dom';
-import classNames from 'classnames';
+
 import { FormattedMessage, injectIntl, defineMessages } from 'react-intl';
+
+import classNames from 'classnames';
+
 import { Icon } from 'flavours/glitch/components/icon';
 
 const messages = defineMessages({