The self-heal timer runs 'systemctl list-unit-files | grep -q' every hour.
When grep matches and exits early, systemctl logs "Failed to print table:
Broken pipe" to syslog. This is cosmetic but floods Proxmox logs and
confuses operators.
Changes:
- Redirect stderr from systemctl to /dev/null
- Prevents the broken pipe message from reaching syslog
- Self-heal functionality unchanged
This addresses the concern raised in discussion #628.