Tell the navbar when a disconnection happens.

src/App/Container.purs

@@ -588,6 +588,8 @@ handleAction = case _ of
   Disconnection -> do
     H.put $ initialState unit
 
+    handleAction $ ToggleAuthenticated Nothing
+
     -- Remove all stored session data.
     sessionstorage <- H.liftEffect $ Window.sessionStorage =<< HTML.window
     H.liftEffect $ Storage.clear sessionstorage