Comment 2 for bug 1725170

Reviewed: https://review.openstack.org/513651
Committed: https://git.openstack.org/cgit/openstack/kolla-ansible/commit/?id=175c65e4900c9cc68917242fd7c9677fc32a2087
Submitter: Zuul
Branch: master

commit 175c65e4900c9cc68917242fd7c9677fc32a2087
Author: Jeffrey Zhang <email address hidden>
Date: Fri Oct 20 16:13:21 2017 +0800

    Remove check flat network type task in ironic pre-check.yml

    flat network type is not mandatory. There are two cases,

    1. ironic with flat network: we can use neutron vlan network to
       provision baremetal nodes, as long as the interface of the baremetal
       nodes are configured to use the same vlan.

    2. ironic with neutron network: all provision and cleaning_network can
       be vlan type and no flat is needed at all.

    So we should remove the task.

    Change-Id: I176ded6d2a8b14e350f665f63bc37eb488d32679
    Closes-Bug: #1725170