Rescue of volume-based instances is supported since Nova
microversion 2.87.
However, Horizon does not use this microversion when requesting
rescue of any instances, causing a Nova exception for volume-
based ones.
The patch fixes this by explicitly setting the required
microversion.
Closes-Bug: #1941744
Signed-off-by: Jan Hartkopf <jhartkopf@inovex.de>
Change-Id: Ic0cdfd326475882f839fd218cd7b4bfa62a2a76b
05dd53a3cf