zeroconf_bonjour can not resolve services over IPv6
On my IPv6-only network, Gajim on Linux can see Gajim on MacOS, but not the other way around.
I think this is because in
service_resolved_callback(), the call to
pybonjour.DNSServiceQueryRecord() only asks for
pybonjour.kDNSServiceType_A, while for IPv6 we need
The respective bit in the Avahi code seem to get the protocol as an argument in
new_service_callback(), but I can't find this in the Bonjour code.