There are scenarios where the config-changed hook can complete, yet the
service IP get configured many seconds after, because a relation-changed
hook execution needs to be triggered on the hacluster side of the
relation.
This change adds a retry to the check (10 times with a 2 seconds wait
time).
This issue was found at the gate https://review.opendev.org/c/openstack/charm-designate-bind/+/861417