MINOR: quic: Wrong ack_delay compution before calling quic_loss_srtt_update()

RFC 9002 5.3. Estimating smoothed_rtt and rttvar:
MUST use the lesser of the acknowledgment delay and the peer's max_ack_delay
after the handshake is confirmed.
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 0a1ef8e..f81d044 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -2208,7 +2208,9 @@
 				unsigned int ack_delay;
 
 				ack_delay = !quic_application_pktns(qel->pktns, qc) ? 0 :
-					MS_TO_TICKS(QUIC_MIN(quic_ack_delay_ms(&frm.ack, qc), qc->max_ack_delay));
+					HA_ATOMIC_LOAD(&qc->state) >= QUIC_HS_ST_CONFIRMED ?
+					MS_TO_TICKS(QUIC_MIN(quic_ack_delay_ms(&frm.ack, qc), qc->max_ack_delay)) :
+					MS_TO_TICKS(quic_ack_delay_ms(&frm.ack, qc));
 				quic_loss_srtt_update(&qc->path->loss, rtt_sample, ack_delay, qc);
 			}
 			break;