[TC-297] Handle domain name for ntp servers in ORT Check

[limited]

From GH issue #566:

check_ntp doesn't handle domain name in the ntp.conf. It also doesn't handle pool of servers. Seems to only handle an IP address.

Not sure if that's actually possible. Would a check if "NTP" is sync'd be enough?

Does it cause a problem? No.
Does it report an error? Yes.

Author: Steve Malenfant
JIRA Link: https://issues.apache.org/jira/browse/TC-297
Found Version: 2.1.0

[smalenfant]

ntpd is not supported anymore in Centos 8. Deprecated in Centos 7. This ntp check should be removed from ORT.