Fix variable collision between AWS CloudFormation Fn::Sub and bash
Fix variable collision between AWS CloudFormation Fn::Sub and bash

Fixes bug in #1139

gdestuynder/MozDef,jeffbryner/MozDef,mpurzynski/MozDef,mozilla/MozDef,Phrozyn/MozDef,jeffbryner/MozDef,jeffbryner/MozDef,mozilla/MozDef,mpurzynski/MozDef,Phrozyn/MozDef,gdestuynder/MozDef,Phrozyn/MozDef,mozilla/MozDef,gdestuynder/MozDef,gdestuynder/MozDef,mozilla/MozDef,jeffbryner/MozDef,mpurzynski/MozDef,Phrozyn/MozDef,mpurzynski/MozDef