replace with custom superagent based on fetch API

src/dns/ovh.js

@@ -21,7 +21,7 @@ const assert = require('assert'),
     waitForDns = require('./waitfordns.js');
 
 function formatError(error) {
-    return `OVH DNS error ${error.error} ${error.message}`; // error.error is the statusCode
+    return `OVH DNS error ${error.error} ${error.message}`; // error.error is the status
 }
 
 function removePrivateFields(domainObject) {