An easier way to test fallback config with address tweak

[cccp6]

Apart from the complicated method by adding host file entries to make things work, we can just access our xray server with ip and add a "@" followed by the domain name of the fallback dest server.
So it looks like https://122.222.222.223@google.com
This makes the browser directly access the IP address while also passing correct sni. No more bothering.
Inspired by a bug report about internet explorer's address bar not showing real destination back in the 2000s.