Fix: 823: Watchdog dies and kills pgpool2 when network gets shortly interrupted.

Fix: 823: Watchdog dies and kills pgpool2 when network gets shortly interrupted.

With network monitoring enabled, a Pgpool node would shut down immediately if it
lost all network interfaces or assigned IP addresses, providing extra protection
by quickly removing a non-communicative node from the cluster.

The issue was that Pgpool responded to network blackout events even when network
monitoring was disabled. This fix ensures that the network monitoring socket is
not opened when network monitoring is not enabled, preventing unnecessary shutdowns.