Comment 5 for bug 1831885

Reviewed: https://review.opendev.org/672611
Committed: https://git.openstack.org/cgit/openstack/tripleo-heat-templates/commit/?id=8833c2da2dcd7c78282d0d5494bb6280f03dd115
Submitter: Zuul
Branch: master

commit 8833c2da2dcd7c78282d0d5494bb6280f03dd115
Author: Kevin Carter <email address hidden>
Date: Wed Jul 24 19:07:33 2019 -0500

    Correct jinja loop logic for role_networks

    The `_role_networks` variable in network loops was being defined and then
    potentially redefined in a larger loop. If this option is first populated
    with a None type and then later discovers a hash the deployment will fail
    with a stack trace:

        'None' has no attribute 'append'

    A full traceback from the error can be seen here[0]. To reolsve this
    issue the empty array, `_role_networks` has been moved into the
    `role.networks` case statement which will ensure the option is type safe
    for every round.

    [0] - https://pasted.tech/pastes/edba7903977c841901c0e655850d4f8b08b32e6c.raw

    Closes-Bug: #1831885
    Change-Id: I480786ed4d6b0a5544535ce232ae8206d04299b1
    Signed-off-by: Kevin Carter <email address hidden>