Fix isInternalUrl for subdomain support

Refactor / reduce plumbing

app/components/Empty.js

@@ -0,0 +1,20 @@
+// @flow
+import * as React from 'react';
+import styled from 'styled-components';
+
+type Props = {
+  children: string,
+};
+
+const Empty = (props: Props) => {
+  const { children, ...rest } = props;
+  return <Container {...rest}>{children}</Container>;
+};
+
+const Container = styled.div`
+  display: flex;
+  color: ${props => props.theme.slate};
+  text-align: center;
+`;
+
+export default Empty;