the new member of struct dns_db that holds a reference count for the database is called 'references', not 'refcount',
a syntax error was introduced in the designated initializer for 'rpsdb_rdataset_methods',
rpsdb_destroy() no longer takes a 'dbp' argument.
Address all of the above issues to make DNSRPS-enabled builds work again.
We should preferably merge this before the March code freeze as the breakage was introduced in this release cycle.
See also !7601 (merged) for an attempt at detecting the type of breakage addressed by this MR in advance.
Closes #3891 (closed)