Disable the interface-interval timer on systems where route/netlink messages work

This issue is essentially a follow-up from #3059 and !5638 (merged).

The idea is that there is no point in having interface-interval on the systems where a kernel reliably informs us about the state of network interfaces. On such systems, having interface-interval is redundant. At the very least the list of such systems includes all Linux distributions, where NetLink messages are available for that.

We may wish to disable the timer with a WARNING message in the log earlier during 9.19 release series to see how well it will work on practice (it should work just fine, IMO).