This incorrect disk_cachemodes setting was causing nova-compute to set
'none' as the disk cache instead of 'writeback'. We want to use
writeback instead because we don't care about data integrity on nodepool
guests.
Change-Id: I9b31c4afa8b7836f2f77294033d0a92bec55dd84
Bump the OSA SHA to pull in a bug fix that causes the os-keystone-install
and os-nova-install playbooks to crash when haproxy is running in a
container.
Related-Bug: #1790779
Change-Id: I3fff6ef22dba039b17bcfe0a74594df7a9972c0d