Steps to reproduce:

1. Add `MySQL by Zabbix agent 2` on host
2. Modify Macros
3. Go to the LLD item `Replication discovery`
4. test it

Result:

if LDD contains special character, it failed with error : 
Cannot fetch data: Error 1227: Access denied; you need (at least one of) the SUPER, SLAVE MONITOR privilege(s) for this operation.

with a simple password the LLD is OK.

special character tested: `: [ {  /`