Add dupe pluralized options to --no-deb and --no-rpm, as --no-debs/--no-...

...rpms.

When I use this packager on either CentOS or Debian, I end up always typing --no-debs rather than --no-deb, as somehow that seems more correct to type out from my mind. It isn't a valid option, and hence I always end up having to run the script twice, second time with the right opts.

This is a nitpick change, perhaps even having to do with my mind's workings, it is alright with me if the request isn't considered. Just thought I'll do the changes anyway.

Thanks!