Ignore SAWarnings for "Evaluating non-mapped column expression"
Ignore SAWarnings for "Evaluating non-mapped column expression"

These warnings come from oslo.db code (tracked with bug 1814199)
so there isn't much nova can do about that right now, outside of
monkey patching oslo.db which is a bad idea.

Let's ignore the warning until the bug in oslo.db is fixed to
avoid blowing up our unit/functional test console output logs
which in turn is intermittently triggering subunit.parser failures.

Change-Id: Ifdfeadae8b348d788de2cd665544015366271d66
Related-Bug: #1813147

mahak/nova,openstack/nova,mahak/nova,rahulunair/nova,klmitch/nova,rahulunair/nova,openstack/nova,klmitch/nova,klmitch/nova,klmitch/nova,rahulunair/nova,openstack/nova,mahak/nova