Disable parallel deployments of modules (fixes Bad Request: Conflict)

[luuksommers]

Deploying sxa and the bootloader on azure using the modules are handled in parallel by default (see https://docs.microsoft.com/en-us/azure/azure-resource-manager/resource-group-create-multiple section Serial Copy).

When deploying MSDeploy packages concurrent a Bad Request: Conflict is thrown during the deployment.

This patch prevents concurrent deployments of the modules.

[RobsonAutomator]

This also happens during installation from Azure Marketplace.

[luuksommers]

We've noticed it during the deployment of SXA

[BevanG]

This has fixed deployment errors for me. Thanks very much! Am able to deploy 9.1.1 into Azure now.