Description of the problem:

MTA will loop infinitely if user provides and invalid userGroup.

How reproducible:

100%

Steps to reproduce:

1. Deploy Orchestrator

2. Deploy workflows

3. Run MTA workflow with below inputs:

repositoryURL: 123456
backstageUser: default/guest
backstageGroup: default

Actual results:

Workflow loops forever 

Expected results:

Workflow exits early with good error message