fix toremove loopback addresses

[v-kamerdinerov]

Looks like there was already a similar problem as long as 2 years ago.

#1107

I checked, indeed if you join the sets IPs correctly to remove addresses - they are removed without problems

exabgp.conf

name = rhel01
interval = 5
command = curl -sf http://10.30.3.13:9005/healthcheck
ip = 10.30.4.3
ip = 10.30.4.4
start-ip = 2
ip = 10.30.4.5
next-hop = 10.30.3.13
withdraw-on-down
dynamic-ip-setup

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet 10.30.6.5/32 scope global lo
       valid_lft forever preferred_lft forever
    inet 10.30.6.4/32 scope global lo
       valid_lft forever preferred_lft forever
    inet 10.30.6.3/32 scope global lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever

Stop loopback ips service (haproxy in my case)

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever

Seems working fine