Function normalize_vault_addr 

pub fn normalize_vault_addr(s: &str) -> String

Normalize a vault address so bare IPs and hostnames work. Prepends https:// when no scheme is present and appends a default port when none is specified: :80 for http://, :443 for https://, :8200 for bare hostnames (Vault’s default). The default scheme is https:// because production Vault always uses TLS. Dev-mode users can set http:// explicitly.