DriverVolumeBlockDevice will delete volume attachment when attach
fails, codes link:
https://github.com/openstack/nova/blob/907c7d2cf/nova/virt/block_device.py#L561-L568
However, nova.compute.manager will delete it again and it will raise
VolumeAttachmentNotFound exception. This outputs an incorrect error
log and this exception should be ignored.
NOTE(mriedem): There are a couple of Queens-only changes to the
unit test due to I4436f5c1cc819c55ca9186bda0362bb74555c95a and
Id587967ea4f9980c292492e2f659bf55fb037b28 not being in stable/queens.
Change-Id: I939c09e5b0efb3b17a9855af227e6d60c64d23e2
Closes-Bug: #1812969
(cherry picked from commit 595866eb62)
(cherry picked from commit 1a684f6fbe)