MINOR: quic: add missing include in quic_sock

Add quic_sock.h include in corresponding source file quic_sock.c.
diff --git a/src/quic_sock.c b/src/quic_sock.c
index 38a8aab..080853f 100644
--- a/src/quic_sock.c
+++ b/src/quic_sock.c
@@ -17,6 +17,7 @@
 
 #include <haproxy/connection.h>
 #include <haproxy/listener.h>
+#include <haproxy/quic_sock.h>
 #include <haproxy/session.h>
 #include <haproxy/xprt_quic.h>