Added missing pseudo-package to list.
Added missing pseudo-package to list.

"listarchives" is not present in the dak list of pseudo-packages, but is
present on http://www.debian.org/Bugs/pseudo-packages.

Signed-off-by: Jonny Lamb <54cd04502facfcf96b325c60af9b1611ee761860@jonnylamb.com>

lamby/debian-devel-changes-bot,lamby/debian-devel-changes-bot,xtaran/debian-devel-changes-bot,sebastinas/debian-devel-changes-bot,lamby/debian-devel-changes-bot,xtaran/debian-devel-changes-bot