Rollback engine api version to 1.11.6 for 6.0.6.0 backports

[jeffngo]

** Expected Behavior**
Engine API version should be set to 1.11.6 to run translators for 6.0.6.0

** Actual Behavior**
Engine API version is set to 1.12.0 and no translators run for 6.0.6.0

Steps To Reproduce the Problem
Run blackbox tests with 6.0.6.0 backports.