frr-reload: fix bgp nbr remote-as

frr-reload: fix bgp nbr remote-as

Remove neighbor <> remote-as <> config line,
if the neighbor is part of the peer-group and
peer-group contains remote-as config.

Neighbors which are part of the peer-group
cannot override remote-as.

Fix:
Frr-reload needs to remote 'neighbor <> remote-as <>'
from lines_to_add if its already part of peer-group
and peer-group has remote-as config.

Testing Done:

Before:

Config snippet:
neighbor PEERS peer-group
neighbor PEERS remote-as external
neighbor PEERS timers 3 9
neighbor 10.2.1.1 remote-as external
neighbor 10.2.1.1 peer-group PEERS
neighbor 10.2.1.1 timers 3 9
neighbor 10.2.1.2 remote-as external
neighbor 10.2.1.2 peer-group PEERS

Frr-reload failure:
line 179: Failure to communicate[13] to bgpd, line:  neighbor 10.2.1.1
remote-as external
% Peer-group member cannot override remote-as of peer-group
line 179: Failure to communicate[13] to bgpd, line:  neighbor 10.2.1.2
remote-as external
% Peer-group member cannot override remote-as of peer-group

After:
frr-reload apply the config successfully.

Signed-off-by: Chirag Shah <chirag@nvidia.com>