mysql: remove grep filter workaround for logs
mysql: remove grep filter workaround for logs

Since I01e6c65d18f3a1889f8aaa75e2e6f68175bbc608 was landed, we don't
need the workaround which pulled out some logs we didn't want to parse.

Change-Id: Ibee22da33391a5e67de02fe08c634a887c9bfa69
Related-Bug: #1811384

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates