Fixes: #8888
* Fix `LogMessage` formatting placeholders in `MqttHeaderMapper`
**cherry-pick to `6.2.x` & `6.1.x`
(cherry picked from commit 8b877fc887)
Fixes: #8888
* Fix `LogMessage` formatting placeholders in `MqttHeaderMapper`
**cherry-pick to `6.2.x` & `6.1.x`
(cherry picked from commit 8b877fc887)