Correct error name for rejecting an unauthorized access token

lib/indieauth/check-scope.js

@@ -25,7 +25,7 @@ module.exports = (requiredScope, tokenScope) => {
   if (!tokenScope) {
     throw new IndieKitError({
       status: 401,
-      error: 'Unauthorized',
+      error: 'Insufficient scope',
       error_description: 'Access token does not provide any scope(s)'
     });
   }