env config in launch debug mode is not respected.

Environment

• Operating System: windows 10
• JDK version: 1.8
• Visual Studio Code version: 1.26.1
• Java extension version: 0.29.0
• Java Debugger extension version: 0.12.0

Steps To Reproduce

1. Add a launch config in launch.json and env block
   "env" : {
   "EdgeHubConnectionString": "aaa",
   "EdgeModuleCACertificateFile": "bbbb"
   }

2. Debug the program. The env variables could not be got.