Updated openstack/openstack
Project: openstack/neutron  3a4a1110b1f2ccd8e2c5477efc8cfdd7ecd5ea51

Big Switch: Retry on 503 errors from backend

Retries requests to the backend controller up to 3
additional times with 3 seconds in between each request
if a 503 service unavailable message was returned.
The scenarios that return 503 messages from floodlight
are normally short lived locks for things like OpenStack
synchronization or upgrade blocks. Retrying should work
in the majority of cases.

Closes-Bug: #1357105
Change-Id: Ifacd3a384cfc797ba6d6af5f3c8649c333473259