slave and simple_user_policy plugins don't work together

[Daniel Nichter]

The slave and simple_user_policy plugins do not work together because the slave plugin does not use a user, therefore the following error is logged:

(SQLSTATE 00000) Access denied for user '<no user>' to schema 'sys_replication'
Failure while executing:
COMMIT
CREATE SCHEMA IF NOT EXISTS `sys_replication` REPLICATE=FALSE

Could not start slave services: (SQLSTATE 00000) Access denied for user '<no user>' to schema 'sys_replication'

Since the slave plugin can't create its sys_replicaiton table, it can't work.

Possible solution: --slave.user and --slave.password options so the slave plugin can operate as the specified user.

Workaround: use regex_policy and ".+ schema=sys_replication ACCEPT".