[Glitch] Use the new JSX transform everywhere

Port 8f66126b10 to glitch-soc

app/javascript/flavours/glitch/features/account_timeline/containers/header_container.jsx

@@ -1,4 +1,3 @@
-import React from 'react';
 import { connect } from 'react-redux';
 import { makeGetAccount, getAccountHidden } from 'flavours/glitch/selectors';
 import Header from '../components/header';