Netflix Preferred CDN: Failed

Looks like in debian 13 without dig installed, every test Netflix CDN Failed,
It's this [line](https://github.com/lmc999/RegionRestrictionCheck/blob/main/check.sh#L112) grep output failed, then I found this [commit](https://github.com/lmc999/RegionRestrictionCheck/commit/22a885f0b73a204d511e658842a7eae47cf50ad8), if I revert to not use `-w` after grep, or delete `\s`, it output successful.