Fix option parsing in 1.2.1

[Michael DeHaan]

There's  a minor problem with option parsing in 1.2.1, as pointed out on 
IRC just now.

cobbler distro edit --name=foo --parameter=value # works
cobbler distro edit --name foo --parameter value  # does not work and 
prints usage

This seems to fix things and is already applied to both branches:

http://git.fedorahosted.org/git/cobbler?p=cobbler;a=commitdiff;h=f1f7cd28...

Since 1.2 is new, we'll hold off for a week or so and then do a 1.2.2 
with any other fixes we might need to include from everyone's testing.

Thanks!

--Michael