Revert "resolve: check DNSSD service name template before assigning it"

Revert "resolve: check DNSSD service name template before assigning it"

This reverts commit 34136e1503cf60852051adbd8b9a002d6282b750.

Having the "%H" host name specifier in a DNSSD service name template
triggers a failed assertion during name template instantiation as
specifier_dnssd_host_name expects DnssdService in its userdata
pointer but finds NULL instead.