DoH query id should always be 0 according to RFC 8484 #77
Description
According to RFC 8484 section 4.1, the id should always be 0 to optimize caching:
In order to maximize HTTP cache friendliness, DoH clients using media formats that include the ID field from the DNS message header, such as "application/dns-message", SHOULD use a DNS ID of 0 in every DNS request. HTTP correlates the request and response, thus eliminating the need for the ID in a media type such as "application/dns-message". The use of a varying DNS ID can cause semantically equivalent DNS queries to be cached separately.
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