vyos.ifconfig: T7814: suppress unnecessary syslog noise from missing nftables rules

When tearing down interfaces without VRF bindings, nftables may attempt to
remove non-existent rules. This results in repetitive error messages in syslog,
e.g.:

  Sep 13 10:27:59 python3[90301]: DEBUG/IFCONFIG returned (err):
  Sep 13 10:27:59 Error[90301]: Could not process rule: No such file or directory
  Sep 13 10:27:59 python3[90301]: delete element inet vrf_zones ct_iface_map { "eth1.1337" }
  Sep 13 10:27:59 python3[90301]:

Such output is noise and provides no operational value. The rule removal logic
has been adjusted to silently ignore errors when the interface or rule is
already absent, ensuring nftables cleanup proceeds when needed while keeping
syslogs clean and meaningful.

0 files changed, 0 insertions, 0 deletions