Bug#40708: Sometimes DB mysqltest1 did not removed before

starting test rpl_row_create_table therefore the patch add 
the cleanup operation if DB with such name already exists. 

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

@@ -436,11 +436,13 @@ reset master;
 reset slave;
 drop table if exists t1,t2,t3,t4,t5,t6,t7,t8,t9;
 start slave;
+DROP DATABASE IF EXISTS mysqltest1;
 CREATE DATABASE mysqltest1;
 CREATE TABLE mysqltest1.without_select (f1 BIGINT);
 CREATE TABLE mysqltest1.with_select AS SELECT 1 AS f1;
 show binlog events from <binlog_start>;
 Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+master-bin.000001	#	Query	#	#	DROP DATABASE IF EXISTS mysqltest1
 master-bin.000001	#	Query	#	#	CREATE DATABASE mysqltest1
 master-bin.000001	#	Query	#	#	use `test`; CREATE TABLE mysqltest1.without_select (f1 BIGINT)
 master-bin.000001	#	Query	#	#	use `test`; BEGIN

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

@@ -266,6 +266,9 @@ sync_slave_with_master;
 source include/master-slave-reset.inc;
 
 connection master;
+--disable_warnings
+DROP DATABASE IF EXISTS mysqltest1;
+--enable_warnings
 CREATE DATABASE mysqltest1;
 
 CREATE TABLE mysqltest1.without_select (f1 BIGINT);