Apparently we forgot about DLZ when updating DNS_CLIENTINFO_VERSION
constant for ECS, which is at value "3" since ECS was introduced.
The code in example drivers and tests now hardcodes version numbers
2 (without ECS) and 3 (with ECS) depending on what a given code path
requires.
(cherry picked from commit f81debe1c8)
34f6cce2c6