Updated openstack/openstack
Project: openstack/neutron  1457f8168c38bdabb416cc55db7694a7a3b47b6b

Fix missing migration default value

Fix 128e042a2b68_ext_gw_mode and 40b0aff0302e_mlnx_initial
migrations by properly using server_default parameter in column
definitions.

Change-Id: I199e206dccc36fcfc2457a17167c76611d69784a
Closes-bug: #1336556