modified to handle the case where nmap does not output a service for the port at all

[ajcrazyo]

Allows the script to continue in cases where nmap does not provide a service in the xml output for a given port like in the example xml below

<host starttime="1645128783" endtime="1645129225"><status state="up" reason="echo-reply" reason_ttl="114"/>
<address addr="x.x.x.x" addrtype="ipv4"/>
<hostnames>
<hostname name="xxxx" type="PTR"/>
</hostnames>
<ports><extraports state="filtered" count="65472">
<extrareasons reason="no-responses" count="65472"/>
</extraports>
<port protocol="tcp" portid="25"><state state="open" reason="syn-ack" reason_ttl="120"/><service name="smtp" method="table" conf="3"/></port>
<port protocol="tcp" portid="43"><state state="open" reason="syn-ack" reason_ttl="119"/><service name="whois" method="table" conf="3"/></port>
<port protocol="tcp" portid="80"><state state="open" reason="syn-ack" reason_ttl="56"/><service name="http" method="table" conf="3"/></port>
<port protocol="tcp" portid="5900"><state state="open" reason="syn-ack" reason_ttl="119"/><service name="vnc" method="table" conf="3"/></port>
<port protocol="tcp" portid="5901"><state state="open" reason="syn-ack" reason_ttl="56"/><service name="vnc-1" method="table" conf="3"/></port>
<port protocol="tcp" portid="6379"><state state="open" reason="syn-ack" reason_ttl="120"/><service name="redis" method="table" conf="3"/></port>
<port protocol="tcp" portid="8062"><state state="open" reason="syn-ack" reason_ttl="119"/></port>
<port protocol="tcp" portid="8063"><state state="open" reason="syn-ack" reason_ttl="120"/></port>
<port protocol="tcp" portid="8075"><state state="open" reason="syn-ack" reason_ttl="120"/></port>
<port protocol="tcp" portid="8080"><state state="open" reason="syn-ack" reason_ttl="56"/><service name="http-proxy" method="table" conf="3"/></port>
<port protocol="tcp" portid="8081"><state state="open" reason="syn-ack" reason_ttl="56"/><service name="blackice-icecap" method="table" conf="3"/></port>

[martijnf1]

Does it help to bump this PR or are we just screaming in the void? can someone just click the merge button?