Fixed MCS env var update in /etc/default/mdsd  (#981)
Fixed MCS env var update in /etc/default/mdsd  (#981)

* Fixed /etc/default/mdsd env var update

* Fixed /etc/default/mdsd env var update

vityagi/azure-linux-extensions,Azure/azure-linux-extensions,Azure/azure-linux-extensions,vityagi/azure-linux-extensions,vityagi/azure-linux-extensions,vityagi/azure-linux-extensions,Azure/azure-linux-extensions,bpramod/azure-linux-extensions,Azure/azure-linux-extensions,Azure/azure-linux-extensions,bpramod/azure-linux-extensions,bpramod/azure-linux-extensions,Azure/azure-linux-extensions,Azure/azure-linux-extensions,vityagi/azure-linux-extensions,vityagi/azure-linux-extensions,vityagi/azure-linux-extensions,bpramod/azure-linux-extensions,bpramod/azure-linux-extensions,bpramod/azure-linux-extensions,bpramod/azure-linux-extensions