Bug#994504: Don't just say "not a real package"

[積丹尼 Dan Jacobson]

Package: aptitude
Version: 0.8.13-3
Severity: wishlist

$ aptitude show ttf-unifont
Package: ttf-unifont
State: not a real package
$ apt show ttf-unifont
Package: ttf-unifont
State: not a real package (virtual)

That's a little better.