Better nail down where QUIC is possibly being used

src/main.rs

@@ -196,11 +196,12 @@ async fn handle_client_query(
             Ok(x) => x,
             Err(_) => {
                 let packet = encrypted_packet;
-                if let Some(synth_packet) = serve_certificates(
+                match serve_certificates(
                     &packet,
                     &globals.provider_name,
                     &dnscrypt_encryption_params_set,
-                )? {
+                ) {
+                    Ok(Some(synth_packet)) => {
                         return encrypt_and_respond_to_query(
                             globals,
                             client_ctx,
@@ -210,9 +211,11 @@ async fn handle_client_query(
                             None,
                             None,
                         )
-                    .await;
+                        .await
                     }
-                bail!("Unencrypted query or QUIC protocol");
+                    Ok(None) => return Ok(()),
+                    Err(_) => bail!("Unencrypted query or QUIC protocol"),
+                };
             }
         };
     ensure!(packet.len() >= DNS_HEADER_SIZE, "Short packet");