MDEV-13545 sql_sequence.gtid fails in buildbot

mysql-test/suite/sql_sequence/gtid.result

@@ -231,6 +231,8 @@ read_only	OFF
 select next value for s_db.s1;
 next value for s_db.s1
 1
+connection master;
+connection slave;
 connection s_normal_3;
 show global variables like 'read_only';
 Variable_name	Value

mysql-test/suite/sql_sequence/gtid.test

@@ -225,6 +225,9 @@ create sequence s_db.s1;
 show global variables like 'read_only';
 select next value for s_db.s1;
 
+connection master;
+sync_slave_with_master;
+
 connection s_normal_3;
 show global variables like 'read_only';
 --error ER_OPTION_PREVENTS_STATEMENT