Remove incorrect compute min_microversions

Many compute tests assume that the min_microversion
is 2.10; however, this assumption is incorrect [0].

This patch removes these incorrect min_microversions.

[0] https://review.openstack.org/#/c/462996/

Change-Id: Idb030b8c63949bd16af93e402971ce8855e41938
Closes-Bug: #1692174
5 files changed