fix: Missing not found page

closes #3476
closes #3531

app/routes/settings.tsx

@@ -1,5 +1,6 @@
 import * as React from "react";
 import { Switch, Redirect } from "react-router-dom";
+import Error404 from "~/scenes/Error404";
 import Route from "~/components/ProfiledRoute";
 import useAuthorizedSettingsConfig from "~/hooks/useAuthorizedSettingsConfig";
 
@@ -20,6 +21,7 @@ export default function SettingsRoutes() {
       <Redirect from="/settings/import-export" to="/settings/export" />
       <Redirect from="/settings/people" to="/settings/members" />
       <Redirect from="/settings/profile" to="/settings" />
+      <Route component={Error404} />
     </Switch>
   );
 }