Move environment variables to middleware. Closes #972.

hooks/useForceSSL.js

@@ -1,14 +0,0 @@
-import { useEffect } from 'react';
-import { useRouter } from 'next/router';
-
-export default function useForceSSL(enabled) {
-  const router = useRouter();
-
-  useEffect(() => {
-    if (enabled && typeof window !== 'undefined' && /^http:\/\//.test(location.href)) {
-      router.push(location.href.replace(/^http:\/\//, 'https://'));
-    }
-  }, [enabled]);
-
-  return null;
-}