List the Registered NameServers associated with a domain.
Sample Request Response<namesilo>
<request>
<operation>listRegisteredNameServers</operation>
<ip>55.555.55.55</ip>
</request>
<reply>
<code>300</code>
<detail>success</detail>
<hosts>
<host>ns1</host>
<ip>123.456.78.9</ip>
<ip>11.22.33.44</ip>
</hosts>
<hosts>
<host>ns2</host>
<ip>99.88.77.6</ip>
</hosts>
</reply>
</namesilo>