lets the following situation:
I have 5 interfaces (vlans) and 5 vrrp groups and I'm going to create 6th.
I've crated 6th vrrp group but forget to create 6th vlan interface and execute "commit" command.
In such situation the VRRP will stop working completely!
log:
```
Aug 15 22:38:11 R9 Keepalived_vrrp[29368]: Opening file '/etc/keepalived/keepalived.conf'.
Aug 15 22:38:11 R9 Keepalived_vrrp[29368]: (Line 61) WARNING - interface eth0.356 for vrrp_instance VLAN-356 doesn't exist
Aug 15 22:38:11 R9 Keepalived_vrrp[29368]: Non-existent interface specified in configuration
Aug 15 22:38:11 R9 Keepalived_vrrp[29368]: Stopped
Aug 15 22:38:11 R9 Keepalived[29367]: Keepalived_vrrp exited with permanent error CONFIG. Terminating
```