[ostf] Need to rewrite error messages for HA ostf tests

[Anastasia Palkina]

Reproduced on ISO #278
"build_id": "2014-06-30_00-31-14",
"mirantis": "yes",
"build_number": "278",
"ostf_sha": "7171951202a22d8dfe9b3b76c9824001e2485630",
"nailgun_sha": "bcb3f0795acbd21f4882103c735a64051492cf7f",
"production": "docker",
"api": "1.0",
"fuelmain_sha": "74ee2ba18e29f81917227767bbf77dfc4c9ffc1d",
"astute_sha": "d1d54d57b3ce1b2f975cbc16c354f1ae7b3391ee",
"release": "5.1",
"fuellib_sha": "c6adc9f28e722f3845da49e45f1e1729d6f6b1a0"

1. Create new environment (Ubuntu, HA mode)
2. Choose VLAN segmentation
3. Choose both Ceph
4. Choose Sahara, Murano, Ceilometer
5. Add controller+ceph, 2 controller+mongo, compute+mongo
6. Start deployment. It has failed
7. Start OSTF tests
8. Three of HA tests have failed

Need to add point before "Please..." for error messages:
- Mysql node detection failed Please refer to OpenStack logs for more details.
- Can list tables Please refer to OpenStack logs for more details.

Need to delete word "cluster" from messages. For example, from this message: "Number of controllers is not equal to number of cluster nodes."
Also this message is not not clear for user.

[Dennis Dmitriev (ddmitriev)]

Issue was fixed in the bug https://review.openstack.org/#/c/168428/ .
Close this one as resolved.