vim: allow editing of crontab without an error on macOS
vim: allow editing of crontab without an error on macOS

Avoids:

    crontab: temp file must be edited in place

when running `crontab -e`.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent