Blacklist: Reinstate 'unspecified' version for the BSA

This commit reinstates the 'unspecified' version for the BSA, as it
can be useful for components like 'WWW'.

In the future we can either
- Hard-code this option for specific components, or
- Eliminate it (e.g. if we have a separate Bugzilla install and
  can make 'WWW' a separate project)