Revert r362809: Mention FreeBSD in the HISTORY sections of apropos(1) and makewhatis(8).

We don't mention the first appearance of a utility in FreeBSD, when it first
appeared in a BSD version that predates FreeBSD.

PR: 223520, 223521
Reported by: rgrimes, imp
Reviewed by: bcr (mentor)
Approved by: bcr (mentor)
Differential Revision: https://reviews.freebsd.org/D25521