Remove the JAIL option.

[mat]

Also force the setuid bit on icmp and dhcp.

[dvl]

That patch works for me when built from poudriere:

$ ./check_ping -H www.google.ca -w 3000.0,80% -c 5000.0,100% -p 1 -6
PING OK - Packet loss = 0%, RTA = 34.69 ms|rta=34.691002ms;3000.000000;5000.000000;0.000000 pl=0%;80;100;0