Rename etc/periodic/daily/430.status-rwho to periodic/daily/430.status-uptime

The command was checking local/remote system uptime, so rename the script to
match its function and to avoid confusion

The controlling variable in /etc/periodic.conf has been renamed from
daily_status_rwho_enable to daily_status_uptime_enable.

MFC after: 3 days
Reported by: Peter Jeremy <peter@rulingia.com>
Relnotes: yes
Sponsored by: EMC / Isilon Storage Division