Dual-stack fixes for Upstreams by #798

Co-Authored-By: brekotis <93345790+brekotis@users.noreply.github.com>

src/proxy/tests/client_masking_redteam_expected_fail_tests.rs

@@ -47,6 +47,7 @@ fn build_harness(secret_hex: &str, mask_port: u16) -> RedTeamHarness {
             selected_scope: String::new(),
             ipv4: None,
             ipv6: None,
+            prefer: None,
         }],
         1,
         1,
@@ -240,6 +241,7 @@ async fn redteam_03_masking_duration_must_be_less_than_1ms_when_backend_down() {
                 selected_scope: String::new(),
                 ipv4: None,
                 ipv6: None,
+                prefer: None,
             }],
             1,
             1,
@@ -484,6 +486,7 @@ async fn measure_invalid_probe_duration_ms(delay_ms: u64, tls_len: u16, body_sen
                 selected_scope: String::new(),
                 ipv4: None,
                 ipv6: None,
+                prefer: None,
             }],
             1,
             1,
@@ -561,6 +564,7 @@ async fn capture_forwarded_probe_len(tls_len: u16, body_sent: usize) -> usize {
                 selected_scope: String::new(),
                 ipv4: None,
                 ipv6: None,
+                prefer: None,
             }],
             1,
             1,