Weight for haproxy backend was merged in [1] with
tiny bug, there is need to convert to int to check
conditional <= 256. Otherwise, it's not working as
expected.

[1] https://review.opendev.org/c/openstack/kolla-ansible/+/775627

Change-Id: Icb6f5147ebd2a0be52ba4ef6ba4a00bbd0242d3d