make webauthn more optional (#6160)

* make webauthn optional

* hide passkey if domain is not set

src/config.rs

@@ -1525,6 +1525,10 @@ impl Config {
         }
     }
 
+    pub fn is_webauthn_2fa_supported(&self) -> bool {
+        Url::parse(&self.domain()).expect("DOMAIN not a valid URL").domain().is_some()
+    }
+
     /// Tests whether the admin token is set to a non-empty value.
     pub fn is_admin_token_set(&self) -> bool {
         let token = self.admin_token();