MINOR: quic: Attach proxy QUIC stats counters to the QUIC connection

Make usage of EXTRA_COUNTERS_GET() do to so from qc_new_conn().
diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index eb94066..e259c3f 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -792,6 +792,7 @@
 
 	const struct qcc_app_ops *app_ops;
 	unsigned int sendto_err;
+	struct quic_counters *prx_counters;
 };
 
 #endif /* USE_QUIC */
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 5c9b7f2..e8082ac 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -45,6 +45,7 @@
 #include <haproxy/quic_frame.h>
 #include <haproxy/quic_loss.h>
 #include <haproxy/quic_sock.h>
+#include <haproxy/quic_stats-t.h>
 #include <haproxy/quic_stream.h>
 #include <haproxy/cbuf.h>
 #include <haproxy/proto_quic.h>
@@ -4330,8 +4331,13 @@
 	qc->cids = EB_ROOT;
 	/* QUIC Server (or listener). */
 	if (server) {
+		struct proxy *prx;
+
 		l = owner;
+		prx = l->bind_conf->frontend;
 
+		qc->prx_counters = EXTRA_COUNTERS_GET(prx->extra_counters_fe,
+		                                      &quic_stats_module);
 		qc->flags |= QUIC_FL_CONN_LISTENER;
 		qc->state = QUIC_HS_ST_SERVER_INITIAL;
 		/* Copy the initial DCID with the address. */