Fix openstack releases version

The Fuel 5.1 will be destributed with two openstack versions:

* 2014.1.1-5.1 -- for new envs
* 2014.1.1-5.0.2 -- for patching old envs

The release 2014.1.1-5.1 don't should be capable to update old
environments, so we need remove them from the release fixture.

Change-Id: Iddf41c41cc519c8abdd9493e27ea52088d96001e
Blueprint: upgrade-to-5-1
Merge "Fix openstack releases version"