m_unsignedLongDependency was already set but never used.

Behavior of Includes::Includes ctor is now in consistency with
the related switch cases in Includes::add (see: m_includeSalTypesH)

Change-Id: I4cca1bab014ac280b73b7532aadfd5ff2b0b9894
Reviewed-on: https://gerrit.libreoffice.org/57792Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Julien Nabet <serval2412@yahoo.fr>
Tested-by: Jenkins