Remove portupgrade's pkgdb when running pkg2ng
Remove portupgrade's pkgdb when running pkg2ng

This fixes a situation where some packages may fail to register, but linger
around in portupgrade's pkgdb, thus confusing portupgrade if they user
tries to force-reinstall that package using portupgrade

en90/pkg,khorben/pkg,khorben/pkg,khorben/pkg,Open343/pkg,en90/pkg,skoef/pkg,skoef/pkg,junovitch/pkg,Open343/pkg,junovitch/pkg