MDEV-13549: Galera test failures

Fix test case galera_toi_ddl_nonconflicting as we need to wait
until both alter tables are finished on that Galera node.

mysql-test/suite/galera/t/galera_toi_ddl_nonconflicting.test

@@ -17,12 +17,23 @@ CREATE TABLE t1 (f1 INTEGER PRIMARY KEY AUTO_INCREMENT, f2 INTEGER);
 --reap
 INSERT INTO t1 (f1, f2) VALUES (DEFAULT, 234);
 
+--let $wait_condition = SELECT COUNT(*) = 3 FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 't1';
+--source include/wait_condition.inc
+--let $wait_condition = SELECT COUNT(*) = 2 FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_NAME = 't1';
+--source include/wait_condition.inc
+
 SELECT COUNT(*) = 3 FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 't1';
 SELECT COUNT(*) = 2 FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_NAME = 't1';
 SELECT COUNT(*) = 2 FROM t1;
 
 --connection node_1
 --reap
+
+--let $wait_condition = SELECT COUNT(*) = 3 FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 't1';
+--source include/wait_condition.inc
+--let $wait_condition = SELECT COUNT(*) = 2 FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_NAME = 't1';
+--source include/wait_condition.inc
+
 SELECT COUNT(*) = 3 FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME = 't1';
 SELECT COUNT(*) = 2 FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_NAME = 't1';
 SELECT COUNT(*) = 2 FROM t1;