MDEV-4726: Race in mysql-test/suite/rpl/t/rpl_gtid_stop_start.test

Fix a race in test case rpl_gtid_basic.
include/sync_with_master_gtid.inc got confused due to two different
GTIDs both with the same seq_no=9.

mysql-test/suite/rpl/r/rpl_gtid_basic.result

@@ -99,10 +99,8 @@ a	b
 5	j1a
 *** Now move C to D, after letting it fall a little behind ***
 include/stop_slave.inc
-BEGIN;
 INSERT INTO t2 VALUES (6, "i6b");
 INSERT INTO t2 VALUES (7, "i7b");
-COMMIT;
 include/save_master_gtid.inc
 CHANGE MASTER TO master_host = '127.0.0.1', master_port = SERVER_MYPORT_4,
 MASTER_USE_GTID=CURRENT_POS;

mysql-test/suite/rpl/t/rpl_gtid_basic.test

@@ -97,10 +97,8 @@ connection server_3;
 --source include/stop_slave.inc
 
 connection server_1;
-BEGIN;
 INSERT INTO t2 VALUES (6, "i6b");
 INSERT INTO t2 VALUES (7, "i7b");
-COMMIT;
 --source include/save_master_gtid.inc
 
 connection server_3;