Updated openstack/openstack
Project: openstack/ceilometer  b5d614e04303d2e27628fff7137aa8a4e662c954
null
Don't use sqlachemy Metadata as global var

In up>down>up mode migrations are failing due to using of common MetaData.
It should be declared separatly for both of migration methods.

Change-Id: I594c649def9a269033463558ba2aa9313f817ee5
Related-Bug: #1240898