Fix cinder gerrit acl
We need to specify a group, otherwise probably only a user named
"cinder-core" would be allow to set the Review-Priority.
[access "refs/heads/*"]
abandon = group cinder-core
label-Code-Review = -2..+2 group cinder-core
-label-Review-Priority = -1..+2 cinder-core
+label-Review-Priority = -1..+2 group cinder-core
label-Verified = -1..+1 group cinder-ci
label-Workflow = -1..+1 group cinder-core
