Fix to make show = all in config files work correctly- which means show host...

Fix to make show = all in config files work correctly- which means show host up, port open and port closed info. And most important, it means don't throw an en error when show = all is encountered in a config file

things:

- Closed ports
- Open ports
- Up hosts

Note that the following two are equivalent in the config file:

show = open,closed,host
show = all

Pointed out by blkshv:
https://github.com/robertdavidgraham/masscan/issues/190

Addresses:
Gentoo bug @ https://bugs.gentoo.org/show_bug.cgi?id=503400