Changing cluster name to already taken doesn't report any errors

[Alexandra Morozova]

STR:

1. create a cluster '1'
2. create a cluste '2'
3. rename cluster '2' to '1' on dashboard tab

Expected:
error message is shown, name is not applied

Actual:
name is not applied, no error is shown

The same occurs when applying the same value to already existing value

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/232943

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/232943
Committed: https://git.openstack.org/cgit/stackforge/fuel-web/commit/?id=56a1ca6c1889ae5a8378198db65c0168c8c06484
Submitter: Jenkins
Branch: master

commit 56a1ca6c1889ae5a8378198db65c0168c8c06484
Author: Alexandra Morozova <email address hidden>
Date: Thu Oct 8 17:38:02 2015 +0200

    Duplicate name errror is now visible for the user

    Closes-bug: #1491498
    Change-Id: I8987093f4b51a838ab403d4dff5075522967c664

[Anastasia Palkina (apalkina)]

Verified on ISO #151

fuel-createmirror_sha": "fe81731b76071dc0a4ffdf039080732243f5a871", "api": "1.0", "fuelmain_sha": "f5b83e3f0ccfce90b9ca797bc039c9ab50b5ee55", "astute_sha": "a090546d43c770ac27ca81c6f8c78ff0ba4a93e0", "fuel-ostf_sha": "e308a7ad68838f6e012d6d80243eb32b4f7e6c18", "openstack_version": "2015.1.0-8.0", "build_id": "151", "build_number": "151", "auth_required": true, "fuel-library_sha": "d4b67bca618c48332486339f8342413ea9b4bc3b", "fuel-nailgun-agent_sha": "08e0a11cf1f29b705e4b910d9b9db5e9b708b6e3", "fuel-nailgun_sha": "56a1ca6c1889ae5a8378198db65c0168c8c06484", "fuel-agent_sha": "5d2d5e2e9ad4f8bb01e450240d85447608d84b92", "production": "docker", "python-fuelclient_sha": "655db5e96282bbafc4dae54462a01823b6b464cb", "feature_groups": ["mirantis"], "release": "8.0", "release_versions": {"2015.1.0-8.0": {"VERSION": {"fuel-createmirror_sha": "fe81731b76071dc0a4ffdf039080732243f5a871", "api": "1.0", "fuelmain_sha": "f5b83e3f0ccfce90b9ca797bc039c9ab50b5ee55", "astute_sha": "a090546d43c770ac27ca81c6f8c78ff0ba4a93e0", "fuel-ostf_sha": "e308a7ad68838f6e012d6d80243eb32b4f7e6c18", "openstack_version": "2015.1.0-8.0", "build_id": "151", "build_number": "151", "fuel-library_sha": "d4b67bca618c48332486339f8342413ea9b4bc3b", "fuel-nailgun-agent_sha": "08e0a11cf1f29b705e4b910d9b9db5e9b708b6e3", "fuel-nailgun_sha": "56a1ca6c1889ae5a8378198db65c0168c8c06484", "fuel-agent_sha": "5d2d5e2e9ad4f8bb01e450240d85447608d84b92", "production": "docker", "python-fuelclient_sha": "655db5e96282bbafc4dae54462a01823b6b464cb", "feature_groups": ["mirantis"], "release": "8.0"}}}