Device URL is no longer correct for national cloud

[andyneff]

When I go to log into a national cloud, I used to get the correct link for authenticating the device Code, however it now always gives the public cloud link instead, and does not work. This creates a blocking problem for users not aware of this error.

Expected behavior

./azcopy_linux_amd64_10.28.0/azcopy login --aad-endpoint https://login.microsoftonline.us

INFO: Authentication is required. To sign in, open the webpage https://microsoft.com/deviceloginus and enter the code ABCDEFGHI to authenticate.

Observed Behavior in 10.28.0

./azcopy_linux_amd64_10.28.0/azcopy login --aad-endpoint https://login.microsoftonline.us

INFO: Authentication is required. To sign in, open the webpage https://aka.ms/devicelogin and enter the code ABCDEFGHI to authenticate.

Old working behavior

This is working in 10.27.1:

$ azcopy login --aad-endpoint https://login.microsoftonline.us
INFO: azcopy 10.27.1: A newer version 10.28.0 is available to download

To sign in, use a web browser to open the page https://microsoft.com/deviceloginus and enter the code ABCDEFGHI to authenticate.

INFO: Logging in under the "Common" tenant. This will log the account in under its home tenant.
INFO: If you plan to use AzCopy with a B2B account (where the account's home tenant is separate from the tenant of the target storage account), please sign in under the target tenant with --tenant-id

[andyneff]

This behavior changed in #2887

Commit e11ecec:

INFO: azcopy 10.28.0-Preview: A newer version 10.28.0 is available to download

INFO: Authentication is required. To sign in, open the webpage https://aka.ms/devicelogin and enter the code ABCDEFGHI to authenticate.

Commit 30eb5f6:

INFO: azcopy 10.28.0-Preview: A newer version 10.28.0 is available to download

To sign in, use a web browser to open the page https://microsoft.com/deviceloginus and enter the code ABCDEFGHI to authenticate.

If I comment out these four lines, I get the correct URL again.