Blizzard made a last-minute change to the Awakening the Machine world even in the Ringing Deeps! The mount from the achievement has been moved to the Awakened Cache.
What’s Changed?
Previously, you would receive 
Machine Defense Unit 1-11 from the 
It’s Not Much, But It’s Honest Work achievement. However, this is no longer the case.
Blizzard recently deployed a hotfix that moved the mount reward to the Awakened Cache that you can open at Gundargaz. Now, every time you open the chest, it has a small chance to contain the mount. You can open it every 5 waves.
