pyntpq: "rv 0" should work

Current:

pyntpq> rv 0
Unknown associd.

Expected:

ntpq> rv 0
associd=0 status=0615 leap_none, sync_ntp, 1 event, clock_sync,
version="ntpd 0.9.5-23acebe Oct 27 2016 02:02:47", processor="x86_64",
system="Linux/4.7.0-1-amd64", leap=00, stratum=2, precision=-23,
rootdelay=46.002, rootdisp=5.549, refid=204.9.54.119,
reftime=dbc54052.ef95284c 2016-11-03T00:49:22.935,
clock=dbc540be.837892bd 2016-11-03T00:51:10.513, peer=33758, tc=4,
mintc=0, offset=1.161494, frequency=-27.124, sys_jitter=2.584654,
clk_jitter=3.188, clk_wander=1.971