Essentially, Bug#45574 results in this bug. The 'CREATE DATABASE IF NOT EXISTS' statement was not 
binlogged, when the database has existed.
Sometimes, the master and slaves become inconsistent. The "CREATE DATABASE
IF NOT EXISTS mysqltest1" statement is not binlogged
if the db 'mysqltest1' existed before the test case is executed. 
So the db 'mysqltest1' can't be created on slave.
     
Patch of Bug#45574 has resolved this problem. 
But I think it is better to replace 'mysqltest1' by default db 'test'.