[Bro] howto append a subnet addr to a set via cmd line...

[Vern Paxson]

>    bro 'SOMENETS += 1.2.3.0/8' myscript.bro

+= doesn't support additions to sets.  Instead use:

	bro -e 'add SOMENETS[1.2.3.0/8]' myscript.bro

- Vern