Use self.warn() for warnings/errors in ntpclients/ntpq.py instead of print()
We want warnings/errors to go to stderr, no stdout.
The remaining calls to print()
should probably be replaced with self.say()
to make it clear that we've made a conscious decision to use stdout.
See https://lists.ntpsec.org/pipermail/devel/2019-January/007045.html