fix vanity NS check

lib/dns-store.js

@@ -407,7 +407,7 @@ module.exports.query = function (input, query, cb) {
       console.log("It's NS");
 
       // If it's a vanity NS, it's not a valid NS for lookup
-      if (-1 !== db.primaryNameservers.indexOf(r.data.toLowerCase())) {
+      if (-1 === db.primaryNameservers.indexOf(r.data.toLowerCase())) {
         console.log("It's a vanity NS");
         return false;
       }