This can be used to detect if the script is executed via the netscript bootoption.
Usage example:
- netcript=server.tld/path/to/script => download and run script/executable from server
+ netscript=server.tld/path/to/script => download and run script/executable from server
netscript=server.tld/script-$HOSTNAME => download and run script/executable for specific host
extract::