Increase performance when receiving messages (#5375)

webapp/root.jsx

@@ -11,7 +11,9 @@ import PDFJS from 'pdfjs-dist';
 import * as GlobalActions from 'actions/global_actions.jsx';
 import * as Websockets from 'actions/websocket_actions.jsx';
 import BrowserStore from 'stores/browser_store.jsx';
+import ChannelStore from 'stores/channel_store.jsx';
 import * as I18n from 'i18n/i18n.jsx';
+import * as AsyncClient from 'utils/async_client.jsx';
 
 // Import our styles
 import 'bootstrap-colorpicker/dist/css/bootstrap-colorpicker.css';
@@ -58,6 +60,7 @@ function preRenderSetup(callwhendone) {
     $(window).on('beforeunload',
          () => {
              BrowserStore.setLastServerVersion('');
+             AsyncClient.viewChannel('', ChannelStore.getCurrentId() || '');
              Websockets.close();
          }
     );