While debugging the support for responding to qemu RX_FILTER_CHANGED
events, I had changed the "ignoring this event" log message from
VIR_DEBUG to VIR_WARN, but forgot to change it back before
pushing. Since many guest OSes make enough changes to multicast lists
and/or promiscuous mode settings to trigger this message, it's
starting to show up as a red herring in bug reports.