MINOR: stream-int: use conn_full_close() instead of conn_force_close()

We simply disable tracking before calling it.
diff --git a/include/proto/stream_interface.h b/include/proto/stream_interface.h
index bafac02..70a3234 100644
--- a/include/proto/stream_interface.h
+++ b/include/proto/stream_interface.h
@@ -160,7 +160,8 @@
 
 	if ((conn = objt_conn(si->end))) {
 		LIST_DEL(&conn->list);
-		conn_force_close(conn);
+		conn_stop_tracking(conn);
+		conn_full_close(conn);
 		conn_free(conn);
 	}
 	else if ((appctx = objt_appctx(si->end))) {