Safetly belt can be disabled with the -F flag
Additionally, add the --not-running-from-cron flag they bypasses the TTY requirement, and allows freebsd-update to be invoked by orchestration frameworks, scripts, or otherwise.
PR: 196760
Differential Revision: https://reviews.freebsd.org/D1550
Reviewed by: cperciva, delphij
Approved by: bcr (mentor), rodrigc (src)
MFC after: 1 month
Relnotes: yes
Sponsored by: ScaleEngine Inc.