Incorrectly classes IP address as domain name

Example:
```ruby
Rex::Socket.is_name?('192.168.1.0')
=> true
```

Expected behaviour:
```ruby
Rex::Socket.is_name?('192.168.1.0')
=> false
```

Example change to the regex being used, taken from https://www.oreilly.com/library/view/regular-expressions-cookbook/9781449327453/ch08s15.html:
```ruby
MATCH_DNS_NAME = /^\b((?=[a-z0-9-]{1,63}\.)(xn--)?[a-z0-9]+(-[a-z0-9]+)*\.)+[a-z]{2,63}\b$/i
```