Fix `export` command failing due to no default HTTPs port

[abhishekkumams]

The default HTTPS address and port have been removed from Kestrel in .NET 7. This introduced a breaking change in DAB after 0.9.7. One of the issue is of export command. Since, it uses https address we see failures.

To fix: Create a fall back mechanism to HTTP address if HTTPS is not enabled.

Can discuss in future to add options in export to use HTTP or HTTPS explicitly #2351