External dependencies update: liboobs

["Elijah Newren" <newren gmail com>]

Hi everyone,

We overlooked liboobs on
http://live.gnome.org/TwoPointSeventeen/ExternalDependencies due to
the gnome-2.18.modules still using the gnome-2-14 branch of
gnome-system-tools.  Seemed like a trivial fix so I added it at
version 0.5.0 after verifying that it works (0.6.0 requires too knew a
version of system-tools-backends).  Just keeping you up to date.  :)

Cheers,
Elijah