Don't compile/install mailwrapper per MK_MAILWRAPPER

OptionalObsoleteFiles.inc was doing the wrong thing by
tying the delete to MK_SENDMAIL == no.

Signed-off-by: Garrett Cooper <yanegomi@gmail.com>
Merge branch 'atf-tools-regression-convert' of github.com:/yaneurabeya/freebsd into atf-tools-regression-convert
Merge branch 'atf-tools-regression-convert' of github.com:/yaneurabeya/freebsd into atf-tools-regression-convert
Merge branch 'atf-tools-regression-convert' of github.com:/yaneurabeya/freebsd into atf-tools-regression-convert