Galera test failure on galera.MDEV-16509

 SET DEBUG_SYNC = "now SIGNAL agac_continue_1";

 SET DEBUG_SYNC = "now SIGNAL agac_continue_2";

CURRENT_TEST: galera.MDEV-16509

--- /usr/share/mysql-test/suite/galera/r/MDEV-16509.result	2019-05-02 02:06:44.000000000 +0000

+++ /dev/shm/var/1/log/MDEV-16509.reject	2019-05-02 08:01:31.045202755 +0000

@@ -65,6 +65,8 @@

 SET DEBUG_SYNC = "now SIGNAL agac_continue_1";

 SET DEBUG_SYNC = "now SIGNAL agac_continue_2";

 connection node_1;

+Warnings:

+Warning	1639	debug sync point wait timed out

 connection node_1a;

 connection ctrl;

 SET DEBUG_SYNC = "RESET";