vrrp: T4182: Check if VRRP configured in op mode
vrrp: T4182: Check if VRRP configured in op mode

There is a situation when service keepalived is active but
there a no any "vrrp" configuration. In that case "show vrrp"
hangs up because it expect data from keepalived daemon which
can't get
Check if "vrrp" exists in configuration and only then check if pid
is active

vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x,vyos/vyos-1x