This release fixes Unknown (0) queries as reported in #1713

Reason: dnsmasq-v2.83+ forwards multiple queries to the same destination once and stores the other queries as duplicates. They do receive the answer later on, however, this is usually not logged (when log-queries=extra is enabled, there will be a warning about the duplicate). FTL v5.6 introduces a new reply type 14 = "already forwarded" to fix this.