Hooks missing exections record with postgress DB backend

[xorel]

Description
When using Postgres DB backend, hooks are executed, but the execution record is not created

To Reproduce
Create hook using template

CALL="one.zone.raftstatus"
COMMAND="/$(which echo) testing"
REMOTE="NO"

run onezone list
check hook execution record are missing

Details
In oned.log:

Thu Aug  6 10:36:09 2020 [Z0][HKM][E]: Error executing Hook 0
Thu Aug  6 10:36:09 2020 [Z0][ONE][E]: SQL command was: SELECT IFNULL(MAX(exeid), -1), COUNT(*) FROM hook_log WHERE hkid = 0, error ERROR:  function ifnull(integer, integer) does not exist
LINE 1: SELECT IFNULL(MAX(exeid), -1), COUNT(*) FROM hook_log WHERE ...

It seems in postgresql the IFNULL is called NULLIF (https://www.postgresqltutorial.com/postgresql-nullif/)

Progress Status

• Branch created
• Code committed to development branch
• Testing - QA
• Documentation
• Release notes - resolved issues, compatibility, known issues
• Code committed to upstream release/hotfix branches
• Documentation committed to upstream release/hotfix branches

[christian7007]

#5072 (duplicated)