Steps to reproduce:

1. I have a trigger prototype with following expression

   {Template App Supervisor v2:supervisord.statename[{#PROC_NAME}].regexp(RUNNING)}=0

2. Save it
3. Edit this trigger to be like this (add ',#3' to regexp)

   {Template App Supervisor v2:supervisord.statename[{#PROC_NAME}].regexp(RUNNING,#3)}=0

4. Click 'Update'. Zabbix gives error

   Cannot update trigger prototype "Supervisor proccess {#PROC_NAME} is {ITEM.LASTVALUE} on {HOST.NAME}": trigger prototype cannot be moved to another template or host.

Expected:
Trigger updates successfully