FreeBSD pkg.conf check does not account for manually added packages.

The pkg.conf system file or PACKAGESITE ENV variable must exist to be able to update or install from a remote repository catalog using 'pkg install', but since packages can be manually added using 'pkg add' it makes sense to remove this check.

We still need to keep the '/var/db/pkg/local.sqlite' check, because without the local sqlite3 DB, you've either not installed or initialized pkgng, or you do not have any locally installed packages actively being managed by pkgng; pkgng will exit with status 0 and list no packages if the local.sqlite db does not exist.