Comment 2 for bug 1265839

Reviewed: https://review.openstack.org/109104
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=138242a0b30480ae42f7160d5c3d98dddfe52d8d
Submitter: Jenkins
Branch: master

commit 138242a0b30480ae42f7160d5c3d98dddfe52d8d
Author: Johannes Erdfelt <email address hidden>
Date: Wed Jul 23 13:07:20 2014 -0700

    Remove duplicate index from block_device_mapping table

    Migration 186 (doesn't exist anymore) deleted the column virtual_name
    from the the block_device_mapping table. This ended up modifying an
    index (block_device_mapping_instance_uuid_virtual_name_device_name_idx)
    to be identical to (block_device_mapping_instance_uuid_device_name_idx)

    Closes-Bug: 1265839
    Change-Id: Ib293220eb764e9810212d121ce7889e6aefc266e