don't return Layout while authenticating

embark-ui/src/containers/AppContainer.js

@@ -103,6 +103,8 @@ class AppContainer extends Component {
   renderBody() {
     if (this.shouldRenderLogin()) {
       return <Login credentials={this.props.credentials} authenticate={this.props.authenticate} error={this.props.authenticationError} />;
+    } else if (this.props.credentials.authenticating) {
+      return <div></div>;
     }
     return (
       <Layout location={this.props.location}