improve download reliability for exporting VHD's from unmanaged disks
When recently trying to backup our test environment VM's from Azure, we ran into issues exporting VHD's from unmanaged disks, which only allowed us to export and download the VHD using an HTTP URL. The download would fail sometimes only seconds into the download, and other times a half hour or so in, but at 2 MB/second, the TTL on the URL would usually expire before we could re-initiate the download, and due to frequency makes it impractical to use. After working with support, they advised we can move the data from an unmanaged disk to a managed one and then export it, but that would increase our cost temporarily, when our goal is to decrease storage costs as it is. My work-around was to use Firefox with an extension called "Download Auto-Resume", which automatically retries failed downloads without user intervention to overcome our issues.