bgpd: Apply NOOP when doing negative commands for GR operations

bgpd: Apply NOOP when doing negative commands for GR operations

E.g.:

```
% The Graceful Restart command used is not valid at this moment.
zsh: exit 1     vtysh -c configure -c 'router bgp' -c 'no neighbor 127.0.0.1 graceful-restart
1
```

This does not make sense frr-reload to fail.

Instead, just ignore such requests if they are just NOOP.

Signed-off-by: Donatas Abraitis <donatas@opensourcerouting.org>
(cherry picked from commit 9ebdb8e80d83a9087deaffee93df4bc90ab6e7ee)