Don't log warnings about invalid packets (Fixes lathiat/avahi#10)
Don't log warnings about invalid packets (Fixes lathiat/avahi#10)

Various invalid packets would generate a warning, in particular
Windows 10 generates response packets with no answer records and
generally seemingly empty.  Unsure why at this stage.

This results in spamming syslog quite a lot on busy networks,
similar issues like this have occured over time due to changes
in various operating systems and specs (e.g. Avahi #284, #282)

Rather than just disable this single message or case, I have
pre-emptively turned the majority of these bad packet messages
into debug messages.  They can still be output on production
builds if reuqired using the --debug option (no rebuild required).

External References:
https://bugs.launchpad.net/ubuntu/+source/avahi/+bug/1342400
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=794145
https://bugzilla.redhat.com/show_bug.cgi?id=1240711

heftig/avahi-1,lathiat/avahi,lathiat/avahi,lathiat/avahi,heftig/avahi,heftig/avahi,heftig/avahi,heftig/avahi-1,lathiat/avahi,heftig/avahi-1,heftig/avahi,heftig/avahi,lathiat/avahi,lathiat/avahi,heftig/avahi-1,heftig/avahi-1,heftig/avahi-1,heftig/avahi