Updated openstack/openstack
Project: openstack/nova  1c702054f941280c34cf64322220d378019f7eb5

move eventlet GREENDNS override to top level

Instead of working around this in 3 places, only do the import
override at the top level. There were comments left by mikal to do
this after the pbr switch which is now done.

Change-Id: I3ec281dd016ad904e9f323630324e70a002a037d