Revert "Use unbound from ports, it should fix #4020"

This reverts commit f13df0e3f1bf45d8dab01805f757e623165c044f.
Revert "Obsolete unbound from FreeBSD base files, ticket #4020"

This reverts commit 8fde4ae8be00bfe7f9cfec107f6566413f41b5f7.