Revert "fdo#67060 do not package RPM-only install script to DEB packs"

Put back the definition of WITH_RPM: otherwise a build
--with-pkgformat=archive fails since the scripts/install is not built.

Leave in the change to installer that should fix the original DEB bug.

This reverts commit 4f995b395ea347469ca9c7681d2f01f63e966d96.

Change-Id: I0cf4ba003237c66dfb7a0677d6a32a69f8203c6b