BGP:Fix for BFD sessions not getting replayed after quagga restart

BGP:Fix for BFD sessions not getting replayed after quagga restart

Signed-off-by: Radhika Mahankali <radhika@cumulusnetworks.com>
Reviewed-by:   Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by:   Kanna Rajagopal <kanna@cumulusnetworks.com>
Ticket: CM-11055
Reviewed By: CCR-4773
Testing Done: Unit, PTM smoke, BGP neighbor smoke

Issue: bgpd is not replaying the BFD registrations to PTM after quagga restart.

Root Cause: This problem happens when BFD configuration is part of the peer group template. Currently, the BFD configuration is being copied to the peer from template as part of the AF (address family) configuration. But, when the saved config is used after the quagga restart the peer group template is applied to the peer before the AF configuration is configured for the template. Due to this the BFD configuration never gets copied from the template to the peer and the BGP peers have no BFD configuration after the restart

Sample config which failed:
router bgp 100
bgp router-id 10.10.0.1
no bgp default ipv4-unicast
bgp bestpath as-path multipath-relax
neighbor dpeergrp_2 peer-group
neighbor dpeergrp_2 remote-as 100
neighbor dpeergrp_2 bfd
neighbor dpeergrp_2 advertisement-interval 1
neighbor dpeergrp_2 timers connect 1
neighbor dpeergrp_4 peer-group
neighbor dpeergrp_4 remote-as 400
neighbor dpeergrp_4 bfd
neighbor dpeergrp_4 advertisement-interval 1
neighbor dpeergrp_4 timers connect 1
neighbor swp2s0.1 interface peer-group dpeergrp_2
neighbor swp18s3.1 interface peer-group dpeergrp_4
!
address-family ipv4 unicast
redistribute connected route-map redist
neighbor dpeergrp_2 activate
neighbor dpeergrp_2 next-hop-self
neighbor dpeergrp_2 default-originate
neighbor dpeergrp_2 soft-reconfiguration inbound
neighbor dpeergrp_4 activate
neighbor dpeergrp_4 next-hop-self
neighbor dpeergrp_4 default-originate
neighbor dpeergrp_4 soft-reconfiguration inbound
maximum-paths 14
exit-address-family

Fix: Moved the BFD config copy from the peer group AF config copy function to the main peer group config copy function.