Adding support for default icons based on Message type

src/pages/404/Component.js

@@ -3,14 +3,13 @@ import PropTypes from 'prop-types';
 import { translate, Trans } from 'react-i18next';
 
 import Message from 'components/Message';
-import AlertIcon from 'feather-icons/dist/icons/alert-octagon.svg';
 import Header from 'components/Header';
 import Footer from 'components/Footer';
 
 const Component = ({ t }) => (
   <React.Fragment>
     <Header/>
-    <Message type="error" icon={ AlertIcon } heading={ t('404 Page Not Found') }>
+    <Message type="error" heading={ t('404 Page Not Found') }>
       <p><Trans>The page you have requested could not be found</Trans></p>
     </Message>
     <Footer/>