Update python-ml-realtimeserving.yml for Azure Pipelines

.ci/python-ml-realtimeserving.yml

@@ -30,7 +30,6 @@ variables:
   azureresourcegroup: 'python-ml-rts-test'
   workspacename: 'pythonmlrtsws'
   azureregion: 'westus'
-  aksimagename: 'pythonmlrtsaksimg'
   expires : "2019-08-01"
   python_path: "$(System.DefaultWorkingDirectory)/architectures/Python-ML-RealTimeServing/{{cookiecutter.project_name}}/"