Updated openstack/openstack
Project: openstack/neutron  600e3d8f7c2b825647b9db5527a5d38b1564fde4

Raise exception if ipv6 prefix is inappropriate for address mode

Address prefix to use with slaac and stateless ipv6 address modes
should be equal to 64 in order to work properly.
The patch adds corresponding validation and fixes unit tests
accordingly.

Change-Id: I6c344b21a69f85f2885a72377171f70309b26775
Closes-Bug: #1357084