Switch netcat to stop parsing command line at first nonoption argument instead of...

Switch netcat to stop parsing command line at first nonoption argument instead of stopping after -l or -L.

Hyejin Kim tried "toyboxd nc nc -p 1234 -l rm mv ps" (which attempted to run
"nc rm mv ps") and "toybox nc -l -p 1234" (which attempted to run "-p 1234")
and found the behavior confusing. So make it work like xargs, where all
netcat options have to come before the start of any child command.